725655651621 has 16 divisors (see below), whose sum is σ = 972486993600. Its totient is φ = 481299073920.

The previous prime is 725655651607. The next prime is 725655651649. The reversal of 725655651621 is 126156556527.

It is not a de Polignac number, because 725655651621 - 2²³ = 725647263013 is a prime.

It is a super-2 number, since 2×725655651621² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (725655651601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1506055 + ... + 1928603.

It is an arithmetic number, because the mean of its divisors is an integer number (60780437100).

Almost surely, 2^725655651621 is an apocalyptic number.

It is an amenable number.

725655651621 is a deficient number, since it is larger than the sum of its proper divisors (246831341979).

725655651621 is a wasteful number, since it uses less digits than its factorization.

725655651621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425476.

The product of its digits is 3780000, while the sum is 51.

The spelling of 725655651621 in words is "seven hundred twenty-five billion, six hundred fifty-five million, six hundred fifty-one thousand, six hundred twenty-one".