31821965440 has 256 divisors, whose sum is σ = 83474621280. Its totient is φ = 11551113216.

The previous prime is 31821965419. The next prime is 31821965501. The reversal of 31821965440 is 4456912813.

It can be written as a sum of positive squares in 16 ways, for example, as 25067755584 + 6754209856 = 158328^2 + 82184^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 55150432 + ... + 55151008.

Almost surely, 2^31821965440 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 31821965440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41737310640).

31821965440 is an abundant number, since it is smaller than the sum of its proper divisors (51652655840).

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

31821965440 is a wasteful number, since it uses less digits than its factorization.

31821965440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 787 (or 775 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 43.

The spelling of 31821965440 in words is "thirty-one billion, eight hundred twenty-one million, nine hundred sixty-five thousand, four hundred forty".