721654765536 has 48 divisors (see below), whose sum is σ = 1926451296000. Its totient is φ = 236474441088.

The previous prime is 721654765453. The next prime is 721654765537. The reversal of 721654765536 is 635567456127.

721654765536 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721654765537) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63699736 + ... + 63711063.

It is an arithmetic number, because the mean of its divisors is an integer number (40134402000).

Almost surely, 2^721654765536 is an apocalyptic number.

It is an amenable number.

721654765536 is an abundant number, since it is smaller than the sum of its proper divisors (1204796530464).

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

721654765536 is a wasteful number, since it uses less digits than its factorization.

721654765536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127410871 (or 127410863 counting only the distinct ones).

The product of its digits is 31752000, while the sum is 57.

The spelling of 721654765536 in words is "seven hundred twenty-one billion, six hundred fifty-four million, seven hundred sixty-five thousand, five hundred thirty-six".