721319013 has 12 divisors (see below), whose sum is σ = 1080494688. Its totient is φ = 480879180.

The previous prime is 721319009. The next prime is 721319017. The reversal of 721319013 is 310913127.

It is an interprime number because it is at equal distance from previous prime (721319009) and next prime (721319017).

It is not a de Polignac number, because 721319013 - 2² = 721319009 is a prime.

It is a super-2 number, since 2×721319013² = 1040602237030588338, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721319017) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1483953 + ... + 1484438.

It is an arithmetic number, because the mean of its divisors is an integer number (90041224).

Almost surely, 2^721319013 is an apocalyptic number.

It is an amenable number.

721319013 is a deficient number, since it is larger than the sum of its proper divisors (359175675).

721319013 is an equidigital number, since it uses as much as digits as its factorization.

721319013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2968406 (or 2968394 counting only the distinct ones).

The product of its (nonzero) digits is 1134, while the sum is 27.

The square root of 721319013 is about 26857.3828397333. The cubic root of 721319013 is about 896.8279331255.

The spelling of 721319013 in words is "seven hundred twenty-one million, three hundred nineteen thousand, thirteen".