21519204 has 24 divisors (see below), whose sum is σ = 57384768. Its totient is φ = 6148320.

The previous prime is 21519203. The next prime is 21519209. The reversal of 21519204 is 40291512.

It is a super-2 number, since 2×21519204² = 926152281587232, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21519203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 128007 + ... + 128174.

It is an arithmetic number, because the mean of its divisors is an integer number (2391032).

Almost surely, 2^21519204 is an apocalyptic number.

It is an amenable number.

21519204 is an abundant number, since it is smaller than the sum of its proper divisors (35865564).

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

21519204 is a wasteful number, since it uses less digits than its factorization.

21519204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256195 (or 256193 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 21519204 is about 4638.8796061118. The cubic root of 21519204 is about 278.1476537370.

The spelling of 21519204 in words is "twenty-one million, five hundred nineteen thousand, two hundred four".