3661855256799 has 12 divisors (see below), whose sum is σ = 5292917970912. Its totient is φ = 2439588458400.

The previous prime is 3661855256777. The next prime is 3661855256819. The reversal of 3661855256799 is 9976525581663.

3661855256799 is a `hidden beast` number, since 3 + 6 + 6 + 1 + 8 + 5 + 52 + 567 + 9 + 9 = 666.

It is not a de Polignac number, because 3661855256799 - 2²¹ = 3661853159647 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3661855256729) 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, 137350887 + ... + 137377544.

It is an arithmetic number, because the mean of its divisors is an integer number (441076497576).

Almost surely, 2^{3661855256799} is an apocalyptic number.

3661855256799 is a deficient number, since it is larger than the sum of its proper divisors (1631062714113).

3661855256799 is a wasteful number, since it uses less digits than its factorization.

3661855256799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274729918 (or 274729915 counting only the distinct ones).

The product of its digits is 734832000, while the sum is 72.

The spelling of 3661855256799 in words is "three trillion, six hundred sixty-one billion, eight hundred fifty-five million, two hundred fifty-six thousand, seven hundred ninety-nine".