2158612665 has 32 divisors (see below), whose sum is σ = 3769998336. Its totient is φ = 1045978560.

The previous prime is 2158612661. The next prime is 2158612679. The reversal of 2158612665 is 5662168512.

It is not a de Polignac number, because 2158612665 - 2² = 2158612661 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2158612661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 404404 + ... + 409706.

It is an arithmetic number, because the mean of its divisors is an integer number (117812448).

Almost surely, 2^2158612665 is an apocalyptic number.

It is an amenable number.

2158612665 is a deficient number, since it is larger than the sum of its proper divisors (1611385671).

2158612665 is a wasteful number, since it uses less digits than its factorization.

2158612665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7789.

The product of its digits is 172800, while the sum is 42.

The square root of 2158612665 is about 46460.8724089421. The cubic root of 2158612665 is about 1292.3840026495.

The spelling of 2158612665 in words is "two billion, one hundred fifty-eight million, six hundred twelve thousand, six hundred sixty-five".