21779280908 has 24 divisors (see below), whose sum is σ = 47518431744. Its totient is φ = 8485434000.

The previous prime is 21779280899. The next prime is 21779280931. The reversal of 21779280908 is 80908297712.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21779280908.

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, 35355668 + ... + 35356283.

It is an arithmetic number, because the mean of its divisors is an integer number (1979934656).

Almost surely, 2^21779280908 is an apocalyptic number.

21779280908 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21779280908 is an abundant number, since it is smaller than the sum of its proper divisors (25739150836).

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

21779280908 is a wasteful number, since it uses less digits than its factorization.

21779280908 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70711973 (or 70711971 counting only the distinct ones).

The product of its (nonzero) digits is 1016064, while the sum is 53.

The spelling of 21779280908 in words is "twenty-one billion, seven hundred seventy-nine million, two hundred eighty thousand, nine hundred eight".