21447686871 has 16 divisors (see below), whose sum is σ = 34218532320. Its totient is φ = 13198576320.

The previous prime is 21447686789. The next prime is 21447686893. The reversal of 21447686871 is 17868674412.

21447686871 is a `hidden beast` number, since 2 + 14 + 476 + 86 + 87 + 1 = 666.

It is not a de Polignac number, because 21447686871 - 2¹⁵ = 21447654103 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21447686371) 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, 30551910 + ... + 30552611.

It is an arithmetic number, because the mean of its divisors is an integer number (2138658270).

Almost surely, 2^21447686871 is an apocalyptic number.

21447686871 is a deficient number, since it is larger than the sum of its proper divisors (12770845449).

21447686871 is a wasteful number, since it uses less digits than its factorization.

21447686871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61104543 (or 61104537 counting only the distinct ones).

The product of its digits is 3612672, while the sum is 54.

The spelling of 21447686871 in words is "twenty-one billion, four hundred forty-seven million, six hundred eighty-six thousand, eight hundred seventy-one".