31531512340 has 24 divisors (see below), whose sum is σ = 66281843880. Its totient is φ = 12600096768.

The previous prime is 31531512251. The next prime is 31531512371. The reversal of 31531512340 is 4321513513.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 408201616 + 31123310724 = 20204^2 + 176418^2 .

It is a junction number, because it is equal to n+sod(n) for n = 31531512299 and 31531512308.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 761077 + ... + 801436.

It is an arithmetic number, because the mean of its divisors is an integer number (2761743495).

Almost surely, 2^31531512340 is an apocalyptic number.

It is an amenable number.

31531512340 is an abundant number, since it is smaller than the sum of its proper divisors (34750331540).

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

31531512340 is a wasteful number, since it uses less digits than its factorization.

31531512340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1563531 (or 1563529 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 28.

The spelling of 31531512340 in words is "thirty-one billion, five hundred thirty-one million, five hundred twelve thousand, three hundred forty".