21425304 has 48 divisors (see below), whose sum is σ = 56917800. Its totient is φ = 6719488.

The previous prime is 21425297. The next prime is 21425311. The reversal of 21425304 is 40352412.

It is an interprime number because it is at equal distance from previous prime (21425297) and next prime (21425311).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5392 + ... + 8480.

Almost surely, 2^21425304 is an apocalyptic number.

21425304 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 21425304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28458900).

21425304 is an abundant number, since it is smaller than the sum of its proper divisors (35492496).

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

21425304 is a wasteful number, since it uses less digits than its factorization.

21425304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3132 (or 3111 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 21425304 is about 4628.7475627863. The cubic root of 21425304 is about 277.7424939836.

Adding to 21425304 its reverse (40352412), we get a palindrome (61777716).

The spelling of 21425304 in words is "twenty-one million, four hundred twenty-five thousand, three hundred four".