21519804 has 24 divisors (see below), whose sum is σ = 50296960. Its totient is φ = 7161264.

The previous prime is 21519803. The next prime is 21519811. The reversal of 21519804 is 40891512.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21519803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8787 + ... + 10965.

Almost surely, 2^21519804 is an apocalyptic number.

It is an amenable number.

21519804 is an abundant number, since it is smaller than the sum of its proper divisors (28777156).

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

21519804 is a wasteful number, since it uses less digits than its factorization.

21519804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3009 (or 3007 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 30.

The square root of 21519804 is about 4638.9442764491. The cubic root of 21519804 is about 278.1502388239.

The spelling of 21519804 in words is "twenty-one million, five hundred nineteen thousand, eight hundred four".