21655106671 has 16 divisors (see below), whose sum is σ = 24793413120. Its totient is φ = 18721642720.

The previous prime is 21655106663. The next prime is 21655106687. The reversal of 21655106671 is 17660155612.

It is not a de Polignac number, because 21655106671 - 2³ = 21655106663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21655106611) 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, 203611 + ... + 291148.

It is an arithmetic number, because the mean of its divisors is an integer number (1549588320).

Almost surely, 2^21655106671 is an apocalyptic number.

21655106671 is a deficient number, since it is larger than the sum of its proper divisors (3138306449).

21655106671 is a wasteful number, since it uses less digits than its factorization.

21655106671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 494966.

The product of its (nonzero) digits is 75600, while the sum is 40.

The spelling of 21655106671 in words is "twenty-one billion, six hundred fifty-five million, one hundred six thousand, six hundred seventy-one".