21680976 has 40 divisors (see below), whose sum is σ = 58959520. Its totient is φ = 6846336.

The previous prime is 21680969. The next prime is 21680993. The reversal of 21680976 is 67908612.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10975 + ... + 12798.

It is an arithmetic number, because the mean of its divisors is an integer number (1473988).

Almost surely, 2^21680976 is an apocalyptic number.

It is an amenable number.

21680976 is an abundant number, since it is smaller than the sum of its proper divisors (37278544).

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

21680976 is a wasteful number, since it uses less digits than its factorization.

21680976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23803 (or 23797 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 21680976 is about 4656.2834965238. The cubic root of 21680976 is about 278.8429120452.

The spelling of 21680976 in words is "twenty-one million, six hundred eighty thousand, nine hundred seventy-six".