31713681 has 8 divisors (see below), whose sum is σ = 42820480. Its totient is φ = 20874672.

The previous prime is 31713677. The next prime is 31713683. The reversal of 31713681 is 18631713.

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

It is not a de Polignac number, because 31713681 - 2² = 31713677 is a prime.

It is a super-2 number, since 2×31713681² = 2011515125139522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31713683) 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, 66670 + ... + 67143.

It is an arithmetic number, because the mean of its divisors is an integer number (5352560).

Almost surely, 2^31713681 is an apocalyptic number.

It is an amenable number.

31713681 is a deficient number, since it is larger than the sum of its proper divisors (11106799).

31713681 is a wasteful number, since it uses less digits than its factorization.

31713681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133895.

The product of its digits is 3024, while the sum is 30.

The square root of 31713681 is about 5631.4901225164. The cubic root of 31713681 is about 316.5304907871.

The spelling of 31713681 in words is "thirty-one million, seven hundred thirteen thousand, six hundred eighty-one".