11457991 has 4 divisors (see below), whose sum is σ = 11494912. Its totient is φ = 11421072.

The previous prime is 11457973. The next prime is 11457997. The reversal of 11457991 is 19975411.

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

It is a cyclic number.

It is not a de Polignac number, because 11457991 - 2⁵ = 11457959 is a prime.

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 11457991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11457997) 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, 17991 + ... + 18616.

It is an arithmetic number, because the mean of its divisors is an integer number (2873728).

Almost surely, 2^11457991 is an apocalyptic number.

11457991 is a deficient number, since it is larger than the sum of its proper divisors (36921).

11457991 is an equidigital number, since it uses as much as digits as its factorization.

11457991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36920.

The product of its digits is 11340, while the sum is 37.

The square root of 11457991 is about 3384.9654355695. The cubic root of 11457991 is about 225.4426905690.

The spelling of 11457991 in words is "eleven million, four hundred fifty-seven thousand, nine hundred ninety-one".