31516821380 has 48 divisors (see below), whose sum is σ = 72457447104. Its totient is φ = 11420142720.

The previous prime is 31516821379. The next prime is 31516821439. The reversal of 31516821380 is 8312861513.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 190847 + ... + 315366.

It is an arithmetic number, because the mean of its divisors is an integer number (1509530148).

Almost surely, 2^31516821380 is an apocalyptic number.

It is an amenable number.

31516821380 is an abundant number, since it is smaller than the sum of its proper divisors (40940625724).

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

31516821380 is a wasteful number, since it uses less digits than its factorization.

31516821380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 506516 (or 506514 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 38.

The spelling of 31516821380 in words is "thirty-one billion, five hundred sixteen million, eight hundred twenty-one thousand, three hundred eighty".