13057991 has 4 divisors (see below), whose sum is σ = 13204800. Its totient is φ = 12911184.

The previous prime is 13057973. The next prime is 13058009. The reversal of 13057991 is 19975031.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (13057973) and next prime (13058009).

It is a cyclic number.

It is not a de Polignac number, because 13057991 - 2¹⁸ = 12795847 is a prime.

It is a super-2 number, since 2×13057991² = 341022257912162, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13057691) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73271 + ... + 73448.

It is an arithmetic number, because the mean of its divisors is an integer number (3301200).

Almost surely, 2^13057991 is an apocalyptic number.

13057991 is a deficient number, since it is larger than the sum of its proper divisors (146809).

13057991 is an equidigital number, since it uses as much as digits as its factorization.

13057991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146808.

The product of its (nonzero) digits is 8505, while the sum is 35.

The square root of 13057991 is about 3613.5842317566. The cubic root of 13057991 is about 235.4825815826.

The spelling of 13057991 in words is "thirteen million, fifty-seven thousand, nine hundred ninety-one".