3931681 has 8 divisors (see below), whose sum is σ = 4261824. Its totient is φ = 3605520.

The previous prime is 3931667. The next prime is 3931687. The reversal of 3931681 is 1861393.

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

It is a cyclic number.

It is not a de Polignac number, because 3931681 - 2⁵ = 3931649 is a prime.

It is a super-2 number, since 2×3931681² = 30916230971522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3931687) 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, 1266 + ... + 3076.

It is an arithmetic number, because the mean of its divisors is an integer number (532728).

Almost surely, 2^3931681 is an apocalyptic number.

It is an amenable number.

3931681 is a deficient number, since it is larger than the sum of its proper divisors (330143).

3931681 is a wasteful number, since it uses less digits than its factorization.

3931681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1991.

The product of its digits is 3888, while the sum is 31.

The square root of 3931681 is about 1982.8466909976. The cubic root of 3931681 is about 157.8311634497.

The spelling of 3931681 in words is "three million, nine hundred thirty-one thousand, six hundred eighty-one".