21778986280 has 32 divisors (see below), whose sum is σ = 51885233640. Its totient is φ = 8199147520.

The previous prime is 21778986269. The next prime is 21778986293. The reversal of 21778986280 is 8268987712.

It can be written as a sum of positive squares in 4 ways, for example, as 21399593796 + 379392484 = 146286^2 + 19478^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16013281 + ... + 16014640.

Almost surely, 2^21778986280 is an apocalyptic number.

21778986280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21778986280 is an abundant number, since it is smaller than the sum of its proper divisors (30106247360).

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

21778986280 is a wasteful number, since it uses less digits than its factorization.

21778986280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32027949 (or 32027945 counting only the distinct ones).

The product of its (nonzero) digits is 5419008, while the sum is 58.

The spelling of 21778986280 in words is "twenty-one billion, seven hundred seventy-eight million, nine hundred eighty-six thousand, two hundred eighty".