21992671 has 8 divisors (see below), whose sum is σ = 23897600. Its totient is φ = 20162520.

The previous prime is 21992657. The next prime is 21992693. The reversal of 21992671 is 17629912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21992671 - 2⁵ = 21992639 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21992671.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21992771) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18081 + ... + 19258.

It is an arithmetic number, because the mean of its divisors is an integer number (2987200).

Almost surely, 2^21992671 is an apocalyptic number.

21992671 is a deficient number, since it is larger than the sum of its proper divisors (1904929).

21992671 is a wasteful number, since it uses less digits than its factorization.

21992671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37389.

The product of its digits is 13608, while the sum is 37.

The square root of 21992671 is about 4689.6344207198. The cubic root of 21992671 is about 280.1728142366.

The spelling of 21992671 in words is "twenty-one million, nine hundred ninety-two thousand, six hundred seventy-one".