21168164 has 12 divisors (see below), whose sum is σ = 38239488. Its totient is φ = 10242600.

The previous prime is 21168151. The next prime is 21168209. The reversal of 21168164 is 46186112.

21168164 is nontrivially palindromic in base 13.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85232 + ... + 85479.

It is an arithmetic number, because the mean of its divisors is an integer number (3186624).

Almost surely, 2^21168164 is an apocalyptic number.

It is an amenable number.

21168164 is a deficient number, since it is larger than the sum of its proper divisors (17071324).

21168164 is a wasteful number, since it uses less digits than its factorization.

21168164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170746 (or 170744 counting only the distinct ones).

The product of its digits is 2304, while the sum is 29.

The square root of 21168164 is about 4600.8873057270. The cubic root of 21168164 is about 276.6268919128.

The spelling of 21168164 in words is "twenty-one million, one hundred sixty-eight thousand, one hundred sixty-four".