31321920400 has 45 divisors (see below), whose sum is σ = 75259418611. Its totient is φ = 12527352320.

The previous prime is 31321920367. The next prime is 31321920407. The reversal of 31321920400 is 402912313.

The square root of 31321920400 is 176980.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 18673769104 + 12648151296 = 136652^2 + 112464^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31321920407) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3535176 + ... + 3544024.

Almost surely, 2^31321920400 is an apocalyptic number.

31321920400 is the 176980-th square number.

It is an amenable number.

31321920400 is an abundant number, since it is smaller than the sum of its proper divisors (43937498211).

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

31321920400 is an frugal number, since it uses more digits than its factorization.

31321920400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17716 (or 8856 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 25.

Multiplying 31321920400 by its sum of digits (25), we get a square (783048010000 = 884900²).

31321920400 divided by its sum of digits (25) gives a square (1252876816 = 35396²).

Multiplying 31321920400 by its product of nonzero digits (1296), we get a square (40593208838400 = 6371280²).

The spelling of 31321920400 in words is "thirty-one billion, three hundred twenty-one million, nine hundred twenty thousand, four hundred".