1091634391 has 4 divisors (see below), whose sum is σ = 1095983784. Its totient is φ = 1087285000.

The previous prime is 1091634377. The next prime is 1091634407. The reversal of 1091634391 is 1934361901.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1934361901 = 31 ⋅62398771.

It is a cyclic number.

It is not a de Polignac number, because 1091634391 - 2¹⁷ = 1091503319 is a prime.

It is a super-2 number, since 2×1091634391² = 2383331287227881762, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1091634391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1091634331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2174320 + ... + 2174821.

It is an arithmetic number, because the mean of its divisors is an integer number (273995946).

Almost surely, 2^1091634391 is an apocalyptic number.

1091634391 is a deficient number, since it is larger than the sum of its proper divisors (4349393).

1091634391 is an equidigital number, since it uses as much as digits as its factorization.

1091634391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4349392.

The product of its (nonzero) digits is 17496, while the sum is 37.

The square root of 1091634391 is about 33039.8909047836. The cubic root of 1091634391 is about 1029.6565892588.

It can be divided in two parts, 1091634 and 391, that added together give a square (1092025 = 1045²).

The spelling of 1091634391 in words is "one billion, ninety-one million, six hundred thirty-four thousand, three hundred ninety-one".