21164143 has 16 divisors (see below), whose sum is σ = 28417536. Its totient is φ = 15222240.

The previous prime is 21164141. The next prime is 21164183. The reversal of 21164143 is 34146112.

It is not a de Polignac number, because 21164143 - 2¹ = 21164141 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21164141) 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 15 ways as a sum of consecutive naturals, for example, 9571 + ... + 11572.

It is an arithmetic number, because the mean of its divisors is an integer number (1776096).

Almost surely, 2^21164143 is an apocalyptic number.

21164143 is a deficient number, since it is larger than the sum of its proper divisors (7253393).

21164143 is a wasteful number, since it uses less digits than its factorization.

21164143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21174.

The product of its digits is 576, while the sum is 22.

The square root of 21164143 is about 4600.4503040463. The cubic root of 21164143 is about 276.6093752437.

The spelling of 21164143 in words is "twenty-one million, one hundred sixty-four thousand, one hundred forty-three".