624666661 has 4 divisors (see below), whose sum is σ = 633990112. Its totient is φ = 615343212.

The previous prime is 624666643. The next prime is 624666697. The reversal of 624666661 is 166666426.

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 624666661 - 2¹⁷ = 624535589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (624666631) 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, 4661625 + ... + 4661758.

It is an arithmetic number, because the mean of its divisors is an integer number (158497528).

Almost surely, 2^624666661 is an apocalyptic number.

It is an amenable number.

624666661 is a deficient number, since it is larger than the sum of its proper divisors (9323451).

624666661 is an equidigital number, since it uses as much as digits as its factorization.

624666661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9323450.

The product of its digits is 373248, while the sum is 43.

The square root of 624666661 is about 24993.3323308438. The cubic root of 624666661 is about 854.8359458617.

The spelling of 624666661 in words is "six hundred twenty-four million, six hundred sixty-six thousand, six hundred sixty-one".