21976768 has 112 divisors (see below), whose sum is σ = 52669440. Its totient is φ = 8985600.

The previous prime is 21976763. The next prime is 21976783. The reversal of 21976768 is 86767912.

It is a happy number.

Its product of digits (254016) is a multiple of the sum of its prime factors (126).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21976763) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 414630 + ... + 414682.

Almost surely, 2^21976768 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 21976768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26334720).

21976768 is an abundant number, since it is smaller than the sum of its proper divisors (30692672).

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

21976768 is a wasteful number, since it uses less digits than its factorization.

21976768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126 (or 116 counting only the distinct ones).

The product of its digits is 254016, while the sum is 46.

The square root of 21976768 is about 4687.9385661504. The cubic root of 21976768 is about 280.1052665423.

The spelling of 21976768 in words is "twenty-one million, nine hundred seventy-six thousand, seven hundred sixty-eight".