11931681 has 8 divisors (see below), whose sum is σ = 15925120. Its totient is φ = 7946352.

The previous prime is 11931613. The next prime is 11931691. The reversal of 11931681 is 18613911.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 11931681 - 2⁷ = 11931553 is a prime.

It is a super-2 number, since 2×11931681² = 284730022971522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11931691) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3816 + ... + 6198.

It is an arithmetic number, because the mean of its divisors is an integer number (1990640).

Almost surely, 2^11931681 is an apocalyptic number.

It is an amenable number.

11931681 is a deficient number, since it is larger than the sum of its proper divisors (3993439).

11931681 is a wasteful number, since it uses less digits than its factorization.

11931681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4055.

The product of its digits is 1296, while the sum is 30.

The square root of 11931681 is about 3454.2265414996. The cubic root of 11931681 is about 228.5075450747.

The spelling of 11931681 in words is "eleven million, nine hundred thirty-one thousand, six hundred eighty-one".