31531540000 has 120 divisors (see below), whose sum is σ = 78733459728. Its totient is φ = 12423840000.

The previous prime is 31531539967. The next prime is 31531540009. The reversal of 31531540000 is 4513513.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (31531540009) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1328235 + ... + 1351765.

Almost surely, 2^31531540000 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31531540000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39366729864).

31531540000 is an abundant number, since it is smaller than the sum of its proper divisors (47201919728).

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

31531540000 is an equidigital number, since it uses as much as digits as its factorization.

31531540000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23628 (or 23605 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 22.

The spelling of 31531540000 in words is "thirty-one billion, five hundred thirty-one million, five hundred forty thousand".