625544721 has 16 divisors (see below), whose sum is σ = 927688320. Its totient is φ = 416599920.

The previous prime is 625544707. The next prime is 625544729. The reversal of 625544721 is 127445526.

It is a happy number.

625544721 is a `hidden beast` number, since 62 + 554 + 47 + 2 + 1 = 666.

It is not a de Polignac number, because 625544721 - 2¹³ = 625536529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (625544729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15916 + ... + 38786.

It is an arithmetic number, because the mean of its divisors is an integer number (57980520).

Almost surely, 2^625544721 is an apocalyptic number.

It is an amenable number.

625544721 is a deficient number, since it is larger than the sum of its proper divisors (302143599).

625544721 is a wasteful number, since it uses less digits than its factorization.

625544721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23893 (or 23887 counting only the distinct ones).

The product of its digits is 67200, while the sum is 36.

The square root of 625544721 is about 25010.8920472661. The cubic root of 625544721 is about 855.2362904938.

The spelling of 625544721 in words is "six hundred twenty-five million, five hundred forty-four thousand, seven hundred twenty-one".