3918681 has 12 divisors (see below), whose sum is σ = 6095908. Its totient is φ = 2411424.

The previous prime is 3918667. The next prime is 3918689. The reversal of 3918681 is 1868193.

It can be written as a sum of positive squares in 2 ways, for example, as 2673225 + 1245456 = 1635^2 + 1116^2 .

It is not a de Polignac number, because 3918681 - 2⁷ = 3918553 is a prime.

It is a super-2 number, since 2×3918681² = 30712121559522, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (3918689) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16630 + ... + 16863.

Almost surely, 2^3918681 is an apocalyptic number.

It is an amenable number.

3918681 is a deficient number, since it is larger than the sum of its proper divisors (2177227).

3918681 is a wasteful number, since it uses less digits than its factorization.

3918681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33512 (or 33509 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 3918681 is about 1979.5658614959. The cubic root of 3918681 is about 157.6570165049.

The spelling of 3918681 in words is "three million, nine hundred eighteen thousand, six hundred eighty-one".