721320057 has 12 divisors (see below), whose sum is σ = 1057458480. Its totient is φ = 473702328.

The previous prime is 721320023. The next prime is 721320071. The reversal of 721320057 is 750023127.

It is not a de Polignac number, because 721320057 - 2⁸ = 721319801 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 721320057.

It is not an unprimeable number, because it can be changed into a prime (721320157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 597507 + ... + 598712.

It is an arithmetic number, because the mean of its divisors is an integer number (88121540).

Almost surely, 2^721320057 is an apocalyptic number.

It is an amenable number.

721320057 is a deficient number, since it is larger than the sum of its proper divisors (336138423).

721320057 is a wasteful number, since it uses less digits than its factorization.

721320057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1196292 (or 1196289 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 27.

The square root of 721320057 is about 26857.4022757228. The cubic root of 721320057 is about 896.8283657995.

The spelling of 721320057 in words is "seven hundred twenty-one million, three hundred twenty thousand, fifty-seven".