21878788355 has 16 divisors (see below), whose sum is σ = 26317376064. Its totient is φ = 17461192320.

The previous prime is 21878788319. The next prime is 21878788357. The reversal of 21878788355 is 55388787812.

It is not a de Polignac number, because 21878788355 - 2²⁴ = 21862011139 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21878788357) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 6854810 + ... + 6858000.

It is an arithmetic number, because the mean of its divisors is an integer number (1644836004).

Almost surely, 2^21878788355 is an apocalyptic number.

21878788355 is a deficient number, since it is larger than the sum of its proper divisors (4438587709).

21878788355 is a wasteful number, since it uses less digits than its factorization.

21878788355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6046.

The product of its digits is 30105600, while the sum is 62.

The spelling of 21878788355 in words is "twenty-one billion, eight hundred seventy-eight million, seven hundred eighty-eight thousand, three hundred fifty-five".