21877765444 has 24 divisors (see below), whose sum is σ = 38711826720. Its totient is φ = 10817857536.

The previous prime is 21877765423. The next prime is 21877765451. The reversal of 21877765444 is 44456777812.

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, 66339 + ... + 219445.

It is an arithmetic number, because the mean of its divisors is an integer number (1612992780).

Almost surely, 2^21877765444 is an apocalyptic number.

It is an amenable number.

21877765444 is a deficient number, since it is larger than the sum of its proper divisors (16834061276).

21877765444 is a wasteful number, since it uses less digits than its factorization.

21877765444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153507 (or 153505 counting only the distinct ones).

The product of its digits is 10536960, while the sum is 55.

The spelling of 21877765444 in words is "twenty-one billion, eight hundred seventy-seven million, seven hundred sixty-five thousand, four hundred forty-four".