2164866921 has 36 divisors (see below), whose sum is σ = 3796366912. Its totient is φ = 1164288384.

The previous prime is 2164866889. The next prime is 2164866923. The reversal of 2164866921 is 1296684612.

It is not a de Polignac number, because 2164866921 - 2⁵ = 2164866889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2164866923) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 41245 + ... + 77658.

Almost surely, 2^2164866921 is an apocalyptic number.

2164866921 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2164866921 is a deficient number, since it is larger than the sum of its proper divisors (1631499991).

2164866921 is a wasteful number, since it uses less digits than its factorization.

2164866921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118950 (or 118930 counting only the distinct ones).

The product of its digits is 248832, while the sum is 45.

The square root of 2164866921 is about 46528.1304266569. The cubic root of 2164866921 is about 1293.6309619805.

The spelling of 2164866921 in words is "two billion, one hundred sixty-four million, eight hundred sixty-six thousand, nine hundred twenty-one".