721321704 has 24 divisors (see below), whose sum is σ = 1953579810. Its totient is φ = 240440544.

The previous prime is 721321703. The next prime is 721321751. The reversal of 721321704 is 407123127.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 717704100 + 3617604 = 26790^2 + 1902^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×721321704² = 1040610001322927232, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (721321703) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5009107 + ... + 5009250.

Almost surely, 2^721321704 is an apocalyptic number.

It is an amenable number.

721321704 is an abundant number, since it is smaller than the sum of its proper divisors (1232258106).

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

721321704 is a wasteful number, since it uses less digits than its factorization.

721321704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10018369 (or 10018362 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 721321704 is about 26857.4329376432. The cubic root of 721321704 is about 896.8290483792.

The spelling of 721321704 in words is "seven hundred twenty-one million, three hundred twenty-one thousand, seven hundred four".