31122018 has 12 divisors (see below), whose sum is σ = 67431078. Its totient is φ = 10374000.

The previous prime is 31121999. The next prime is 31122023. The reversal of 31122018 is 81022113.

It can be written as a sum of positive squares in only one way, i.e., 22496049 + 8625969 = 4743^2 + 2937^2 .

It is a Harshad number since it is a multiple of its sum of digits (18), and also a Moran number because the ratio is a prime number: 1729001 = 31122018 / (3 + 1 + 1 + 2 + 2 + 0 + 1 + 8).

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 864483 + ... + 864518.

Almost surely, 2^31122018 is an apocalyptic number.

31122018 is an abundant number, since it is smaller than the sum of its proper divisors (36309060).

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

31122018 is a wasteful number, since it uses less digits than its factorization.

31122018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1729009 (or 1729006 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 31122018 is about 5578.7111414734. The cubic root of 31122018 is about 314.5496815584.

The spelling of 31122018 in words is "thirty-one million, one hundred twenty-two thousand, eighteen".