721625540 has 24 divisors (see below), whose sum is σ = 1536760512. Its totient is φ = 284584160.

The previous prime is 721625539. The next prime is 721625551. The reversal of 721625540 is 45526127.

It is a junction number, because it is equal to n+sod(n) for n = 721625497 and 721625506.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 252674 + ... + 255513.

It is an arithmetic number, because the mean of its divisors is an integer number (64031688).

Almost surely, 2^721625540 is an apocalyptic number.

It is an amenable number.

721625540 is an abundant number, since it is smaller than the sum of its proper divisors (815134972).

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

721625540 is a wasteful number, since it uses less digits than its factorization.

721625540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 508267 (or 508265 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 32.

The square root of 721625540 is about 26863.0888022952. The cubic root of 721625540 is about 896.9549518417.

The spelling of 721625540 in words is "seven hundred twenty-one million, six hundred twenty-five thousand, five hundred forty".