21792887 has 4 divisors (see below), whose sum is σ = 21835080. Its totient is φ = 21750696.

The previous prime is 21792877. The next prime is 21792899. The reversal of 21792887 is 78829712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21792887 - 2²² = 17598583 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 (21792857) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20312 + ... + 21357.

It is an arithmetic number, because the mean of its divisors is an integer number (5458770).

Almost surely, 2^21792887 is an apocalyptic number.

21792887 is a deficient number, since it is larger than the sum of its proper divisors (42193).

21792887 is an equidigital number, since it uses as much as digits as its factorization.

21792887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42192.

The product of its digits is 112896, while the sum is 44.

The square root of 21792887 is about 4668.2852312171. The cubic root of 21792887 is about 279.3218580596.

The spelling of 21792887 in words is "twenty-one million, seven hundred ninety-two thousand, eight hundred eighty-seven".