11975981 has 4 divisors (see below), whose sum is σ = 12000864. Its totient is φ = 11951100.

The previous prime is 11975941. The next prime is 11975983. The reversal of 11975981 is 18957911.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11975981 is a prime.

It is a super-2 number, since 2×11975981² = 286848241824722, 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 (11975983) 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, 11705 + ... + 12686.

It is an arithmetic number, because the mean of its divisors is an integer number (3000216).

Almost surely, 2^11975981 is an apocalyptic number.

It is an amenable number.

11975981 is a deficient number, since it is larger than the sum of its proper divisors (24883).

11975981 is an equidigital number, since it uses as much as digits as its factorization.

11975981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24882.

The product of its digits is 22680, while the sum is 41.

The square root of 11975981 is about 3460.6330345762. The cubic root of 11975981 is about 228.7899970870.

The spelling of 11975981 in words is "eleven million, nine hundred seventy-five thousand, nine hundred eighty-one".