721680625 has 20 divisors (see below), whose sum is σ = 917143920. Its totient is φ = 567530000.

The previous prime is 721680611. The next prime is 721680677. The reversal of 721680625 is 526086127.

It is a happy number.

It is not a de Polignac number, because 721680625 - 2⁵ = 721680593 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 27090 + ... + 46660.

It is an arithmetic number, because the mean of its divisors is an integer number (45857196).

Almost surely, 2^721680625 is an apocalyptic number.

It is an amenable number.

721680625 is a deficient number, since it is larger than the sum of its proper divisors (195463295).

721680625 is an equidigital number, since it uses as much as digits as its factorization.

721680625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19650 (or 19635 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 721680625 is about 26864.1140743558. The cubic root of 721680625 is about 896.9777741614.

The spelling of 721680625 in words is "seven hundred twenty-one million, six hundred eighty thousand, six hundred twenty-five".