31985157 has 16 divisors (see below), whose sum is σ = 44673408. Its totient is φ = 20317440.

The previous prime is 31985147. The next prime is 31985159. The reversal of 31985157 is 75158913.

It is not a de Polignac number, because 31985157 - 2¹¹ = 31983109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31985159) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20857 + ... + 22337.

It is an arithmetic number, because the mean of its divisors is an integer number (2792088).

Almost surely, 2^31985157 is an apocalyptic number.

It is an amenable number.

31985157 is a deficient number, since it is larger than the sum of its proper divisors (12688251).

31985157 is a wasteful number, since it uses less digits than its factorization.

31985157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1820.

The product of its digits is 37800, while the sum is 39.

The square root of 31985157 is about 5655.5421490782. The cubic root of 31985157 is about 317.4311157317.

The spelling of 31985157 in words is "thirty-one million, nine hundred eighty-five thousand, one hundred fifty-seven".