21778986279 has 16 divisors (see below), whose sum is σ = 30047846400. Its totient is φ = 14022313536.

The previous prime is 21778986269. The next prime is 21778986293. The reversal of 21778986279 is 97268987712.

It is not a de Polignac number, because 21778986279 - 2⁸ = 21778986023 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21778986259) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 936999 + ... + 959960.

It is an arithmetic number, because the mean of its divisors is an integer number (1877990400).

Almost surely, 2^21778986279 is an apocalyptic number.

21778986279 is a deficient number, since it is larger than the sum of its proper divisors (8268860121).

21778986279 is a wasteful number, since it uses less digits than its factorization.

21778986279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1897094.

The product of its digits is 42674688, while the sum is 66.

The spelling of 21778986279 in words is "twenty-one billion, seven hundred seventy-eight million, nine hundred eighty-six thousand, two hundred seventy-nine".