31138818 has 16 divisors (see below), whose sum is σ = 64286976. Its totient is φ = 10044720.

The previous prime is 31138817. The next prime is 31138829. The reversal of 31138818 is 81883113.

It is not an unprimeable number, because it can be changed into a prime (31138817) 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, 83521 + ... + 83892.

It is an arithmetic number, because the mean of its divisors is an integer number (4017936).

Almost surely, 2^31138818 is an apocalyptic number.

31138818 is an abundant number, since it is smaller than the sum of its proper divisors (33148158).

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

31138818 is a wasteful number, since it uses less digits than its factorization.

31138818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167449.

The product of its digits is 4608, while the sum is 33.

The square root of 31138818 is about 5580.2166624603. The cubic root of 31138818 is about 314.6062704774.

The spelling of 31138818 in words is "thirty-one million, one hundred thirty-eight thousand, eight hundred eighteen".