21682978880 has 28 divisors (see below), whose sum is σ = 51632594220. Its totient is φ = 8673191424.

The previous prime is 21682978841. The next prime is 21682978921. The reversal of 21682978880 is 8887928612.

It can be written as a sum of positive squares in 2 ways, for example, as 12280185856 + 9402793024 = 110816^2 + 96968^2 .

It is a super-2 number, since 2×21682978880² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33879335 + ... + 33879974.

Almost surely, 2^21682978880 is an apocalyptic number.

21682978880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21682978880 is an abundant number, since it is smaller than the sum of its proper divisors (29949615340).

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

21682978880 is an equidigital number, since it uses as much as digits as its factorization.

21682978880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67759326 (or 67759316 counting only the distinct ones).

The product of its (nonzero) digits is 6193152, while the sum is 59.

The spelling of 21682978880 in words is "twenty-one billion, six hundred eighty-two million, nine hundred seventy-eight thousand, eight hundred eighty".