624661561 has 4 divisors (see below), whose sum is σ = 624860752. Its totient is φ = 624462372.

The previous prime is 624661553. The next prime is 624661571. The reversal of 624661561 is 165166426.

624661561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 624661561 - 2³ = 624661553 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 624661561.

It is not an unprimeable number, because it can be changed into a prime (624661571) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 94815 + ... + 101188.

It is an arithmetic number, because the mean of its divisors is an integer number (156215188).

Almost surely, 2^624661561 is an apocalyptic number.

It is an amenable number.

624661561 is a deficient number, since it is larger than the sum of its proper divisors (199191).

624661561 is a wasteful number, since it uses less digits than its factorization.

624661561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199190.

The product of its digits is 51840, while the sum is 37.

The square root of 624661561 is about 24993.2303034242. The cubic root of 624661561 is about 854.8336194608.

The spelling of 624661561 in words is "six hundred twenty-four million, six hundred sixty-one thousand, five hundred sixty-one".