21760668 has 72 divisors (see below), whose sum is σ = 58889376. Its totient is φ = 6758400.

The previous prime is 21760639. The next prime is 21760679. The reversal of 21760668 is 86606712.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 33628 + ... + 34268.

It is an arithmetic number, because the mean of its divisors is an integer number (817908).

Almost surely, 2^21760668 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 21760668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29444688).

21760668 is an abundant number, since it is smaller than the sum of its proper divisors (37128708).

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

21760668 is a wasteful number, since it uses less digits than its factorization.

21760668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 715 (or 710 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 21760668 is about 4664.8331159860. The cubic root of 21760668 is about 279.1841386654.

The spelling of 21760668 in words is "twenty-one million, seven hundred sixty thousand, six hundred sixty-eight".