921515521936 has 135 divisors (see below), whose sum is σ = 2004414703761. Its totient is φ = 410277514752.

The previous prime is 921515521931. The next prime is 921515521937. The reversal of 921515521936 is 639125515129.

It is a happy number.

The square root of 921515521936 is 959956.

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

It can be written as a sum of positive squares in only one way, i.e., 717442880400 + 204072641536 = 847020^2 + 451744^2 .

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 921515521936.

It is not an unprimeable number, because it can be changed into a prime (921515521931) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1240262781 + ... + 1240263523.

Almost surely, 2^921515521936 is an apocalyptic number.

921515521936 is the 959956-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 921515521936

921515521936 is an abundant number, since it is smaller than the sum of its proper divisors (1082899181825).

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

921515521936 is an equidigital number, since it uses as much as digits as its factorization.

921515521936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1566 (or 781 counting only the distinct ones).

The product of its digits is 729000, while the sum is 49.

Multiplying 921515521936 by its sum of digits (49), we get a square (45154260574864 = 6719692²).

The spelling of 921515521936 in words is "nine hundred twenty-one billion, five hundred fifteen million, five hundred twenty-one thousand, nine hundred thirty-six".