11577981 has 4 divisors (see below), whose sum is σ = 15437312. Its totient is φ = 7718652.

The previous prime is 11577977. The next prime is 11577991. The reversal of 11577981 is 18977511.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 11577981 - 2² = 11577977 is a prime.

It is a super-2 number, since 2×11577981² = 268099288072722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11577961) 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 3 ways as a sum of consecutive naturals, for example, 1929661 + ... + 1929666.

It is an arithmetic number, because the mean of its divisors is an integer number (3859328).

Almost surely, 2^11577981 is an apocalyptic number.

It is an amenable number.

11577981 is a deficient number, since it is larger than the sum of its proper divisors (3859331).

11577981 is an equidigital number, since it uses as much as digits as its factorization.

11577981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3859330.

The product of its digits is 17640, while the sum is 39.

The square root of 11577981 is about 3402.6432372495. The cubic root of 11577981 is about 226.2269172548.

The spelling of 11577981 in words is "eleven million, five hundred seventy-seven thousand, nine hundred eighty-one".