11801591 has 4 divisors (see below), whose sum is σ = 11887872. Its totient is φ = 11715312.

The previous prime is 11801567. The next prime is 11801611. The reversal of 11801591 is 19510811.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19510811 = 31 ⋅629381.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11801591 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 11801591.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11801551) 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, 42935 + ... + 43208.

It is an arithmetic number, because the mean of its divisors is an integer number (2971968).

Almost surely, 2^11801591 is an apocalyptic number.

11801591 is a deficient number, since it is larger than the sum of its proper divisors (86281).

11801591 is an equidigital number, since it uses as much as digits as its factorization.

11801591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86280.

The product of its (nonzero) digits is 360, while the sum is 26.

The square root of 11801591 is about 3435.3443786613. The cubic root of 11801591 is about 227.6740430456.

The spelling of 11801591 in words is "eleven million, eight hundred one thousand, five hundred ninety-one".