21130164 has 36 divisors (see below), whose sum is σ = 58269120. Its totient is φ = 6402960.

The previous prime is 21130111. The next prime is 21130231. The reversal of 21130164 is 46103112.

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, 26284 + ... + 27075.

Almost surely, 2^21130164 is an apocalyptic number.

It is an amenable number.

21130164 is an abundant number, since it is smaller than the sum of its proper divisors (37138956).

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

21130164 is a wasteful number, since it uses less digits than its factorization.

21130164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53380 (or 53375 counting only the distinct ones).

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

The square root of 21130164 is about 4596.7558125269. The cubic root of 21130164 is about 276.4612639716.

Adding to 21130164 its reverse (46103112), we get a palindrome (67233276).

The spelling of 21130164 in words is "twenty-one million, one hundred thirty thousand, one hundred sixty-four".