21887795 has 4 divisors (see below), whose sum is σ = 26265360. Its totient is φ = 17510232.

The previous prime is 21887773. The next prime is 21887797. The reversal of 21887795 is 59778812.

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 21887795 - 2¹⁰ = 21886771 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21887797) 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, 2188775 + ... + 2188784.

It is an arithmetic number, because the mean of its divisors is an integer number (6566340).

Almost surely, 2^21887795 is an apocalyptic number.

21887795 is a deficient number, since it is larger than the sum of its proper divisors (4377565).

21887795 is an equidigital number, since it uses as much as digits as its factorization.

21887795 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4377564.

The product of its digits is 282240, while the sum is 47.

The square root of 21887795 is about 4678.4393765443. The cubic root of 21887795 is about 279.7267529877.

The spelling of 21887795 in words is "twenty-one million, eight hundred eighty-seven thousand, seven hundred ninety-five".