1091377980 has 288 divisors, whose sum is σ = 4214246400. Its totient is φ = 226638720.

The previous prime is 1091377979. The next prime is 1091377981. The reversal of 1091377980 is 897731901.

It is an interprime number because it is at equal distance from previous prime (1091377979) and next prime (1091377981).

It is a super-2 number, since 2×1091377980² = 2382211790457760800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1091377981) 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 95 ways as a sum of consecutive naturals, for example, 678337 + ... + 679943.

It is an arithmetic number, because the mean of its divisors is an integer number (14632800).

Almost surely, 2^1091377980 is an apocalyptic number.

1091377980 is a gapful number since it is divisible by the number (10) 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 1091377980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2107123200).

1091377980 is an abundant number, since it is smaller than the sum of its proper divisors (3122868420).

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

1091377980 is a wasteful number, since it uses less digits than its factorization.

1091377980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1654 (or 1635 counting only the distinct ones).

The product of its (nonzero) digits is 95256, while the sum is 45.

The square root of 1091377980 is about 33036.0103523413. The cubic root of 1091377980 is about 1029.5759652111.

The spelling of 1091377980 in words is "one billion, ninety-one million, three hundred seventy-seven thousand, nine hundred eighty".