3816636561 has 12 divisors (see below), whose sum is σ = 5837209092. Its totient is φ = 2394752256.

The previous prime is 3816636529. The next prime is 3816636619. The reversal of 3816636561 is 1656366183.

3816636561 is a `hidden beast` number, since 3 + 8 + 1 + 6 + 636 + 5 + 6 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1177862400 + 2638774161 = 34320^2 + 51369^2 .

It is not a de Polignac number, because 3816636561 - 2⁵ = 3816636529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3816636511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12472516 + ... + 12472821.

It is an arithmetic number, because the mean of its divisors is an integer number (486434091).

Almost surely, 2^3816636561 is an apocalyptic number.

It is an amenable number.

3816636561 is a deficient number, since it is larger than the sum of its proper divisors (2020572531).

3816636561 is a wasteful number, since it uses less digits than its factorization.

3816636561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24945360 (or 24945357 counting only the distinct ones).

The product of its digits is 466560, while the sum is 45.

The square root of 3816636561 is about 61778.9329869010. The cubic root of 3816636561 is about 1562.7647336056.

The spelling of 3816636561 in words is "three billion, eight hundred sixteen million, six hundred thirty-six thousand, five hundred sixty-one".