21730976 has 24 divisors (see below), whose sum is σ = 44260020. Its totient is φ = 10490368.

The previous prime is 21730963. The next prime is 21730979. The reversal of 21730976 is 67903712.

It can be written as a sum of positive squares in 2 ways, for example, as 21715600 + 15376 = 4660^2 + 124^2 .

It is not an unprimeable number, because it can be changed into a prime (21730979) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 10781 + ... + 12636.

Almost surely, 2^21730976 is an apocalyptic number.

It is an amenable number.

21730976 is an abundant number, since it is smaller than the sum of its proper divisors (22529044).

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

21730976 is a wasteful number, since it uses less digits than its factorization.

21730976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23456 (or 23448 counting only the distinct ones).

The product of its (nonzero) digits is 15876, while the sum is 35.

The square root of 21730976 is about 4661.6494934733. The cubic root of 21730976 is about 279.0571004604.

The spelling of 21730976 in words is "twenty-one million, seven hundred thirty thousand, nine hundred seventy-six".