31620142720 has 128 divisors (see below), whose sum is σ = 77397644880. Its totient is φ = 12349440000.

The previous prime is 31620142691. The next prime is 31620142739. The reversal of 31620142720 is 2724102613.

It can be written as a sum of positive squares in 8 ways, for example, as 22167636544 + 9452506176 = 148888^2 + 97224^2 .

It is a tau number, because it is divible by the number of its divisors (128).

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, 4715370 + ... + 4722070.

Almost surely, 2^31620142720 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 31620142720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38698822440).

31620142720 is an abundant number, since it is smaller than the sum of its proper divisors (45777502160).

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

31620142720 is a wasteful number, since it uses less digits than its factorization.

31620142720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6894 (or 6882 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 28.

The spelling of 31620142720 in words is "thirty-one billion, six hundred twenty million, one hundred forty-two thousand, seven hundred twenty".