21368704 has 48 divisors (see below), whose sum is σ = 49535280. Its totient is φ = 9155328.

The previous prime is 21368651. The next prime is 21368707. The reversal of 21368704 is 40786312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21368707) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4569 + ... + 7975.

It is an arithmetic number, because the mean of its divisors is an integer number (1031985).

Almost surely, 2^21368704 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 21368704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24767640).

21368704 is an abundant number, since it is smaller than the sum of its proper divisors (28166576).

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

21368704 is an equidigital number, since it uses as much as digits as its factorization.

21368704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3435 (or 3416 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 21368704 is about 4622.6295547015. The cubic root of 21368704 is about 277.4977041717.

The spelling of 21368704 in words is "twenty-one million, three hundred sixty-eight thousand, seven hundred four".