21419904 has 96 divisors (see below), whose sum is σ = 62674920. Its totient is φ = 6476800.

The previous prime is 21419903. The next prime is 21419911. The reversal of 21419904 is 40991412.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21419903) 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 11 ways as a sum of consecutive naturals, for example, 46234 + ... + 46694.

Almost surely, 2^21419904 is an apocalyptic number.

21419904 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21419904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31337460).

21419904 is an abundant number, since it is smaller than the sum of its proper divisors (41255016).

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

21419904 is a wasteful number, since it uses less digits than its factorization.

21419904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 500 (or 477 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 21419904 is about 4628.1642148913. The cubic root of 21419904 is about 277.7191580955.

The spelling of 21419904 in words is "twenty-one million, four hundred nineteen thousand, nine hundred four".