21956704 has 144 divisors (see below), whose sum is σ = 58605120. Its totient is φ = 7983360.

The previous prime is 21956699. The next prime is 21956713. The reversal of 21956704 is 40765912.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 21956704.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 327679 + ... + 327745.

It is an arithmetic number, because the mean of its divisors is an integer number (406980).

Almost surely, 2^21956704 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 21956704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29302560).

21956704 is an abundant number, since it is smaller than the sum of its proper divisors (36648416).

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

21956704 is a wasteful number, since it uses less digits than its factorization.

21956704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121 (or 106 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 21956704 is about 4685.7981177170. The cubic root of 21956704 is about 280.0199985716.

The spelling of 21956704 in words is "twenty-one million, nine hundred fifty-six thousand, seven hundred four".