21859671 has 24 divisors (see below), whose sum is σ = 32615680. Its totient is φ = 12984192.

The previous prime is 21859661. The next prime is 21859679. The reversal of 21859671 is 17695812.

It is not a de Polignac number, because 21859671 - 2⁷ = 21859543 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 (21859679) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15810 + ... + 17136.

Almost surely, 2^21859671 is an apocalyptic number.

21859671 is a deficient number, since it is larger than the sum of its proper divisors (10756009).

21859671 is a wasteful number, since it uses less digits than its factorization.

21859671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1383 (or 1366 counting only the distinct ones).

The product of its digits is 30240, while the sum is 39.

The square root of 21859671 is about 4675.4327072475. The cubic root of 21859671 is about 279.6068930824.

The spelling of 21859671 in words is "twenty-one million, eight hundred fifty-nine thousand, six hundred seventy-one".