721713531 has 16 divisors (see below), whose sum is σ = 1199731968. Its totient is φ = 374916000.

The previous prime is 721713521. The next prime is 721713533. The reversal of 721713531 is 135317127.

It is not a de Polignac number, because 721713531 - 2⁶ = 721713467 is a prime.

It is a super-2 number, since 2×721713531² = 1041740841656975922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (721713533) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1561920 + ... + 1562381.

It is an arithmetic number, because the mean of its divisors is an integer number (74983248).

Almost surely, 2^721713531 is an apocalyptic number.

721713531 is a deficient number, since it is larger than the sum of its proper divisors (478018437).

721713531 is a wasteful number, since it uses less digits than its factorization.

721713531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3124322.

The product of its digits is 4410, while the sum is 30.

The square root of 721713531 is about 26864.7265201044. The cubic root of 721713531 is about 896.9914069241.

The spelling of 721713531 in words is "seven hundred twenty-one million, seven hundred thirteen thousand, five hundred thirty-one".