2165657656 has 32 divisors (see below), whose sum is σ = 4207325040. Its totient is φ = 1044223488.

The previous prime is 2165657603. The next prime is 2165657657. The reversal of 2165657656 is 6567565612.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2165657657) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1075 + ... + 65821.

Almost surely, 2^2165657656 is an apocalyptic number.

It is an amenable number.

2165657656 is a deficient number, since it is larger than the sum of its proper divisors (2041667384).

2165657656 is a wasteful number, since it uses less digits than its factorization.

2165657656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64903 (or 64899 counting only the distinct ones).

The product of its digits is 2268000, while the sum is 49.

The square root of 2165657656 is about 46536.6270372059. The cubic root of 2165657656 is about 1293.7884458349.

The spelling of 2165657656 in words is "two billion, one hundred sixty-five million, six hundred fifty-seven thousand, six hundred fifty-six".