721420256 has 24 divisors (see below), whose sum is σ = 1454940144. Its totient is φ = 351911680.

The previous prime is 721420201. The next prime is 721420261. The reversal of 721420256 is 652024127.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 273620 + ... + 276243.

It is an arithmetic number, because the mean of its divisors is an integer number (60622506).

Almost surely, 2^721420256 is an apocalyptic number.

It is an amenable number.

721420256 is an abundant number, since it is smaller than the sum of its proper divisors (733519888).

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

721420256 is a wasteful number, since it uses less digits than its factorization.

721420256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 549914 (or 549906 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 29.

The square root of 721420256 is about 26859.2675998434. The cubic root of 721420256 is about 896.8698901982.

The spelling of 721420256 in words is "seven hundred twenty-one million, four hundred twenty thousand, two hundred fifty-six".