3656638557 has 24 divisors (see below), whose sum is σ = 6205207008. Its totient is φ = 2045671200.

The previous prime is 3656638543. The next prime is 3656638589. The reversal of 3656638557 is 7558366563.

3656638557 is a `hidden beast` number, since 3 + 6 + 56 + 6 + 38 + 557 = 666.

It is not a de Polignac number, because 3656638557 - 2⁴ = 3656638541 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3656638537) 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 in 23 ways as a sum of consecutive naturals, for example, 1419319 + ... + 1421892.

It is an arithmetic number, because the mean of its divisors is an integer number (258550292).

Almost surely, 2^3656638557 is an apocalyptic number.

It is an amenable number.

3656638557 is a deficient number, since it is larger than the sum of its proper divisors (2548568451).

3656638557 is a wasteful number, since it uses less digits than its factorization.

3656638557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2841241 (or 2841238 counting only the distinct ones).

The product of its digits is 13608000, while the sum is 54.

The square root of 3656638557 is about 60470.1459978393. The cubic root of 3656638557 is about 1540.6146078029.

The spelling of 3656638557 in words is "three billion, six hundred fifty-six million, six hundred thirty-eight thousand, five hundred fifty-seven".