21164344 has 8 divisors (see below), whose sum is σ = 39683160. Its totient is φ = 10582168.

The previous prime is 21164327. The next prime is 21164357. The reversal of 21164344 is 44346112.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1322764 + ... + 1322779.

It is an arithmetic number, because the mean of its divisors is an integer number (4960395).

Almost surely, 2^21164344 is an apocalyptic number.

It is an amenable number.

21164344 is a deficient number, since it is larger than the sum of its proper divisors (18518816).

21164344 is a wasteful number, since it uses less digits than its factorization.

21164344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2645549 (or 2645545 counting only the distinct ones).

The product of its digits is 2304, while the sum is 25.

The square root of 21164344 is about 4600.4721496820. The cubic root of 21164344 is about 276.6102509120.

The spelling of 21164344 in words is "twenty-one million, one hundred sixty-four thousand, three hundred forty-four".