721457523 has 12 divisors (see below), whose sum is σ = 1080702168. Its totient is φ = 480971520.

The previous prime is 721457501. The next prime is 721457549. The reversal of 721457523 is 325754127.

721457523 is a `hidden beast` number, since 72 + 14 + 57 + 523 = 666.

It is not a de Polignac number, because 721457523 - 2⁶ = 721457459 is a prime.

It is not an unprimeable number, because it can be changed into a prime (721457323) 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, 1484238 + ... + 1484723.

It is an arithmetic number, because the mean of its divisors is an integer number (90058514).

Almost surely, 2^721457523 is an apocalyptic number.

721457523 is a deficient number, since it is larger than the sum of its proper divisors (359244645).

721457523 is an equidigital number, since it uses as much as digits as its factorization.

721457523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2968976 (or 2968964 counting only the distinct ones).

The product of its digits is 58800, while the sum is 36.

The square root of 721457523 is about 26859.9613365321. The cubic root of 721457523 is about 896.8853333810.

The spelling of 721457523 in words is "seven hundred twenty-one million, four hundred fifty-seven thousand, five hundred twenty-three".