21964878855 has 12 divisors (see below), whose sum is σ = 38072456760. Its totient is φ = 11714602032.

The previous prime is 21964878833. The next prime is 21964878857. The reversal of 21964878855 is 55887846912.

21964878855 is a `hidden beast` number, since 21 + 9 + 6 + 487 + 88 + 55 = 666.

It is not a de Polignac number, because 21964878855 - 2¹¹ = 21964876807 is a prime.

It is a super-2 number, since 2×21964878855² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21964878792 and 21964878801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21964878857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 244054165 + ... + 244054254.

It is an arithmetic number, because the mean of its divisors is an integer number (3172704730).

Almost surely, 2^21964878855 is an apocalyptic number.

21964878855 is a deficient number, since it is larger than the sum of its proper divisors (16107577905).

21964878855 is a wasteful number, since it uses less digits than its factorization.

21964878855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 488108430 (or 488108427 counting only the distinct ones).

The product of its digits is 38707200, while the sum is 63.

The spelling of 21964878855 in words is "twenty-one billion, nine hundred sixty-four million, eight hundred seventy-eight thousand, eight hundred fifty-five".