21864227913 has 32 divisors (see below), whose sum is σ = 35344744320. Its totient is φ = 13247815680.

The previous prime is 21864227911. The next prime is 21864227929. The reversal of 21864227913 is 31972246812.

21864227913 is a `hidden beast` number, since 218 + 6 + 422 + 7 + 9 + 1 + 3 = 666.

It is not a de Polignac number, because 21864227913 - 2¹ = 21864227911 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21864227911) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1876281 + ... + 1887897.

It is an arithmetic number, because the mean of its divisors is an integer number (1104523260).

Almost surely, 2^21864227913 is an apocalyptic number.

It is an amenable number.

21864227913 is a deficient number, since it is larger than the sum of its proper divisors (13480516407).

21864227913 is a wasteful number, since it uses less digits than its factorization.

21864227913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17974 (or 17968 counting only the distinct ones).

The product of its digits is 290304, while the sum is 45.

The spelling of 21864227913 in words is "twenty-one billion, eight hundred sixty-four million, two hundred twenty-seven thousand, nine hundred thirteen".