85631731 has 2 divisors, whose sum is σ = 85631732. Its totient is φ = 85631730.

The previous prime is 85631723. The next prime is 85631747. The reversal of 85631731 is 13713658.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 85631731 - 2³ = 85631723 is a prime.

It is a super-2 number, since 2×85631731² = 14665586708112722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (85631761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42815865 + 42815866.

It is an arithmetic number, because the mean of its divisors is an integer number (42815866).

Almost surely, 2^85631731 is an apocalyptic number.

85631731 is a deficient number, since it is larger than the sum of its proper divisors (1).

85631731 is an equidigital number, since it uses as much as digits as its factorization.

85631731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 34.

The square root of 85631731 is about 9253.7414595395. The cubic root of 85631731 is about 440.7695400328.

The spelling of 85631731 in words is "eighty-five million, six hundred thirty-one thousand, seven hundred thirty-one".