21344164 has 6 divisors (see below), whose sum is σ = 37352294. Its totient is φ = 10672080.

The previous prime is 21344159. The next prime is 21344173. The reversal of 21344164 is 46144312.

It can be written as a sum of positive squares in only one way, i.e., 20793600 + 550564 = 4560^2 + 742^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 2668017 + ... + 2668024.

Almost surely, 2^21344164 is an apocalyptic number.

It is an amenable number.

21344164 is a deficient number, since it is larger than the sum of its proper divisors (16008130).

21344164 is a wasteful number, since it uses less digits than its factorization.

21344164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5336045 (or 5336043 counting only the distinct ones).

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

The square root of 21344164 is about 4619.9744588039. The cubic root of 21344164 is about 277.3914365800.

Adding to 21344164 its reverse (46144312), we get a palindrome (67488476).

The spelling of 21344164 in words is "twenty-one million, three hundred forty-four thousand, one hundred sixty-four".