725821424521 has 12 divisors (see below), whose sum is σ = 771385670172. Its totient is φ = 680585391104.

The previous prime is 725821424483. The next prime is 725821424561. The reversal of 725821424521 is 125424128527.

It can be written as a sum of positive squares in 6 ways, for example, as 69379560000 + 656441864521 = 263400^2 + 810211^2 .

It is a de Polignac number, because none of the positive numbers 2^k-725821424521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (725821424561) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 935121 + ... + 1525153.

It is an arithmetic number, because the mean of its divisors is an integer number (64282139181).

Almost surely, 2^725821424521 is an apocalyptic number.

It is an amenable number.

725821424521 is a deficient number, since it is larger than the sum of its proper divisors (45564245651).

725821424521 is an equidigital number, since it uses as much as digits as its factorization.

725821424521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 590588 (or 590319 counting only the distinct ones).

The product of its digits is 358400, while the sum is 43.

The spelling of 725821424521 in words is "seven hundred twenty-five billion, eight hundred twenty-one million, four hundred twenty-four thousand, five hundred twenty-one".