1091555136 has 448 divisors, whose sum is σ = 3932651520. Its totient is φ = 290304000.

The previous prime is 1091555131. The next prime is 1091555141. The reversal of 1091555136 is 6315551901.

1091555136 is a `hidden beast` number, since 1 + 0 + 91 + 55 + 513 + 6 = 666.

It is an interprime number because it is at equal distance from previous prime (1091555131) and next prime (1091555141).

It is a tau number, because it is divible by the number of its divisors (448).

It is a super-2 number, since 2×1091555136² = 2382985229855956992, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 1091555136.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1091555131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 15373981 + ... + 15374051.

It is an arithmetic number, because the mean of its divisors is an integer number (8778240).

Almost surely, 2^1091555136 is an apocalyptic number.

1091555136 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1091555136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1966325760).

1091555136 is an abundant number, since it is smaller than the sum of its proper divisors (2841096384).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1091555136 is a wasteful number, since it uses less digits than its factorization.

1091555136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171 (or 155 counting only the distinct ones).

The product of its (nonzero) digits is 20250, while the sum is 36.

The square root of 1091555136 is about 33038.6914995131. The cubic root of 1091555136 is about 1029.6316702295.

The spelling of 1091555136 in words is "one billion, ninety-one million, five hundred fifty-five thousand, one hundred thirty-six".