21103164 has 36 divisors (see below), whose sum is σ = 53486160. Its totient is φ = 7015680.

The previous prime is 21103139. The next prime is 21103177. The reversal of 21103164 is 46130112.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22252 + ... + 23180.

Almost surely, 2^21103164 is an apocalyptic number.

It is an amenable number.

21103164 is an abundant number, since it is smaller than the sum of its proper divisors (32382996).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21103164 is a wasteful number, since it uses less digits than its factorization.

21103164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1570 (or 1565 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 21103164 is about 4593.8180199046. The cubic root of 21103164 is about 276.3434602522.

Adding to 21103164 its reverse (46130112), we get a palindrome (67233276).

The spelling of 21103164 in words is "twenty-one million, one hundred three thousand, one hundred sixty-four".