21328504 has 16 divisors (see below), whose sum is σ = 40101120. Its totient is φ = 10634880.

The previous prime is 21328501. The next prime is 21328537. The reversal of 21328504 is 40582312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21328501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 417 + ... + 6544.

It is an arithmetic number, because the mean of its divisors is an integer number (2506320).

Almost surely, 2^21328504 is an apocalyptic number.

It is an amenable number.

21328504 is a deficient number, since it is larger than the sum of its proper divisors (18772616).

21328504 is a wasteful number, since it uses less digits than its factorization.

21328504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7350 (or 7346 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 21328504 is about 4618.2793332582. The cubic root of 21328504 is about 277.3235802064.

The spelling of 21328504 in words is "twenty-one million, three hundred twenty-eight thousand, five hundred four".