11981956 has 24 divisors (see below), whose sum is σ = 24373440. Its totient is φ = 5047392.

The previous prime is 11981941. The next prime is 11981971. The reversal of 11981956 is 65918911.

It is an interprime number because it is at equal distance from previous prime (11981941) and next prime (11981971).

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1975 + ... + 5278.

It is an arithmetic number, because the mean of its divisors is an integer number (1015560).

Almost surely, 2^11981956 is an apocalyptic number.

It is an amenable number.

11981956 is an abundant number, since it is smaller than the sum of its proper divisors (12391484).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

11981956 is a wasteful number, since it uses less digits than its factorization.

11981956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7323 (or 7321 counting only the distinct ones).

The product of its digits is 19440, while the sum is 40.

The square root of 11981956 is about 3461.4962082891. The cubic root of 11981956 is about 228.8280397034.

The spelling of 11981956 in words is "eleven million, nine hundred eighty-one thousand, nine hundred fifty-six".