31531312404 has 18 divisors (see below), whose sum is σ = 79704150890. Its totient is φ = 10510437456.

The previous prime is 31531312403. The next prime is 31531312433. The reversal of 31531312404 is 40421313513.

It is a happy number.

31531312404 is a `hidden beast` number, since 3 + 1 + 531 + 3 + 124 + 0 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 30975296004 + 556016400 = 175998^2 + 23580^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31531312403) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 437934859 + ... + 437934930.

Almost surely, 2^31531312404 is an apocalyptic number.

It is an amenable number.

31531312404 is an abundant number, since it is smaller than the sum of its proper divisors (48172838486).

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

31531312404 is a wasteful number, since it uses less digits than its factorization.

31531312404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 875869799 (or 875869794 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

Adding to 31531312404 its reverse (40421313513), we get a palindrome (71952625917).

The spelling of 31531312404 in words is "thirty-one billion, five hundred thirty-one million, three hundred twelve thousand, four hundred four".