2504165661 has 12 divisors (see below), whose sum is σ = 3714888892. Its totient is φ = 1624323456.

The previous prime is 2504165659. The next prime is 2504165681. The reversal of 2504165661 is 1665614052.

2504165661 is a `hidden beast` number, since 2 + 50 + 41 + 6 + 566 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1291036761 + 1213128900 = 35931^2 + 34830^2 .

It is not a de Polignac number, because 2504165661 - 2¹ = 2504165659 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 (2504165681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3759676 + ... + 3760341.

Almost surely, 2^2504165661 is an apocalyptic number.

It is an amenable number.

2504165661 is a deficient number, since it is larger than the sum of its proper divisors (1210723231).

2504165661 is a wasteful number, since it uses less digits than its factorization.

2504165661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7520060 (or 7520057 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 2504165661 is about 50041.6392717105. The cubic root of 2504165661 is about 1357.9622129021.

The spelling of 2504165661 in words is "two billion, five hundred four million, one hundred sixty-five thousand, six hundred sixty-one".