21164032 has 26 divisors (see below), whose sum is σ = 42331088. Its totient is φ = 10579968.

The previous prime is 21164029. The next prime is 21164047. The reversal of 21164032 is 23046112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1513 + ... + 6679.

Almost surely, 2^21164032 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21164032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21165544).

21164032 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21164032 is an frugal number, since it uses more digits than its factorization.

21164032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5191 (or 5169 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 21164032 is about 4600.4382399941. The cubic root of 21164032 is about 276.6088916633.

The spelling of 21164032 in words is "twenty-one million, one hundred sixty-four thousand, thirty-two".