624385661 has 2 divisors, whose sum is σ = 624385662. Its totient is φ = 624385660.

The previous prime is 624385649. The next prime is 624385709. The reversal of 624385661 is 166583426.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 604225561 + 20160100 = 24581^2 + 4490^2 .

It is a cyclic number.

It is not a de Polignac number, because 624385661 - 2²² = 620191357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (624345661) 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 as a sum of consecutive naturals, namely, 312192830 + 312192831.

It is an arithmetic number, because the mean of its divisors is an integer number (312192831).

Almost surely, 2^624385661 is an apocalyptic number.

It is an amenable number.

624385661 is a deficient number, since it is larger than the sum of its proper divisors (1).

624385661 is an equidigital number, since it uses as much as digits as its factorization.

624385661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 207360, while the sum is 41.

The square root of 624385661 is about 24987.7101992159. The cubic root of 624385661 is about 854.7077468593.

The spelling of 624385661 in words is "six hundred twenty-four million, three hundred eighty-five thousand, six hundred sixty-one".