21430164 has 24 divisors (see below), whose sum is σ = 57147328. Its totient is φ = 6122880.

The previous prime is 21430147. The next prime is 21430169. The reversal of 21430164 is 46103412.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 21430164.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21430169) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 127477 + ... + 127644.

Almost surely, 2^21430164 is an apocalyptic number.

It is an amenable number.

21430164 is an abundant number, since it is smaller than the sum of its proper divisors (35717164).

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

21430164 is a wasteful number, since it uses less digits than its factorization.

21430164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255135 (or 255133 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 21430164 is about 4629.2725130413. The cubic root of 21430164 is about 277.7634929306.

Adding to 21430164 its reverse (46103412), we get a palindrome (67533576).

The spelling of 21430164 in words is "twenty-one million, four hundred thirty thousand, one hundred sixty-four".