2166502665 has 16 divisors (see below), whose sum is σ = 3471437376. Its totient is φ = 1153790400.

The previous prime is 2166502649. The next prime is 2166502717. The reversal of 2166502665 is 5662056612.

It is a happy number.

It is not a de Polignac number, because 2166502665 - 2⁴ = 2166502649 is a prime.

It is a Curzon 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, 94146 + ... + 114875.

It is an arithmetic number, because the mean of its divisors is an integer number (216964836).

Almost surely, 2^2166502665 is an apocalyptic number.

It is an amenable number.

2166502665 is a deficient number, since it is larger than the sum of its proper divisors (1304934711).

2166502665 is a wasteful number, since it uses less digits than its factorization.

2166502665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209720.

The product of its (nonzero) digits is 129600, while the sum is 39.

The square root of 2166502665 is about 46545.7051187325. The cubic root of 2166502665 is about 1293.9566966072.

The spelling of 2166502665 in words is "two billion, one hundred sixty-six million, five hundred two thousand, six hundred sixty-five".