21323004 has 48 divisors (see below), whose sum is σ = 52254720. Its totient is φ = 6758080.

The previous prime is 21322999. The next prime is 21323011. The reversal of 21323004 is 40032312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24277 + ... + 25139.

It is an arithmetic number, because the mean of its divisors is an integer number (1088640).

Almost surely, 2^21323004 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21323004, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26127360).

21323004 is an abundant number, since it is smaller than the sum of its proper divisors (30931716).

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

21323004 is a wasteful number, since it uses less digits than its factorization.

21323004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 970 (or 968 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 21323004 is about 4617.6838349978. The cubic root of 21323004 is about 277.2997402656.

Adding to 21323004 its reverse (40032312), we get a palindrome (61355316).

The spelling of 21323004 in words is "twenty-one million, three hundred twenty-three thousand, four".