2156206165 has 16 divisors (see below), whose sum is σ = 2727403200. Its totient is φ = 1631912832.

The previous prime is 2156206133. The next prime is 2156206181. The reversal of 2156206165 is 5616026512.

It is a cyclic number.

It is not a de Polignac number, because 2156206165 - 2⁵ = 2156206133 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2156206165.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54849 + ... + 85561.

It is an arithmetic number, because the mean of its divisors is an integer number (170462700).

Almost surely, 2^2156206165 is an apocalyptic number.

It is an amenable number.

2156206165 is a deficient number, since it is larger than the sum of its proper divisors (571197035).

2156206165 is a wasteful number, since it uses less digits than its factorization.

2156206165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31476.

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 2156206165 is about 46434.9670507044. The cubic root of 2156206165 is about 1291.9035584845.

The spelling of 2156206165 in words is "two billion, one hundred fifty-six million, two hundred six thousand, one hundred sixty-five".