2165215660 has 24 divisors (see below), whose sum is σ = 4557235536. Its totient is φ = 864127680.

The previous prime is 2165215639. The next prime is 2165215669. The reversal of 2165215660 is 665125612.

It is not an unprimeable number, because it can be changed into a prime (2165215669) 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, 113331 + ... + 131050.

It is an arithmetic number, because the mean of its divisors is an integer number (189884814).

Almost surely, 2^2165215660 is an apocalyptic number.

2165215660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2165215660 is an abundant number, since it is smaller than the sum of its proper divisors (2392019876).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2165215660 is a wasteful number, since it uses less digits than its factorization.

2165215660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244833 (or 244831 counting only the distinct ones).

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

The square root of 2165215660 is about 46531.8778903237. The cubic root of 2165215660 is about 1293.7004220385.

The spelling of 2165215660 in words is "two billion, one hundred sixty-five million, two hundred fifteen thousand, six hundred sixty".