31157136 has 100 divisors (see below), whose sum is σ = 93399900. Its totient is φ = 10015488.

The previous prime is 31157117. The next prime is 31157149. The reversal of 31157136 is 63175113.

It can be written as a sum of positive squares in 2 ways, for example, as 17139600 + 14017536 = 4140^2 + 3744^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 37170 + ... + 37998.

It is an arithmetic number, because the mean of its divisors is an integer number (933999).

Almost surely, 2^31157136 is an apocalyptic number.

31157136 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31157136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46699950).

31157136 is an abundant number, since it is smaller than the sum of its proper divisors (62242764).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31157136 is a wasteful number, since it uses less digits than its factorization.

31157136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 878 (or 863 counting only the distinct ones).

The product of its digits is 1890, while the sum is 27.

The square root of 31157136 is about 5581.8577552639. The cubic root of 31157136 is about 314.6679494186.

The spelling of 31157136 in words is "thirty-one million, one hundred fifty-seven thousand, one hundred thirty-six".