21805795 has 16 divisors (see below), whose sum is σ = 28696320. Its totient is φ = 15775200.

The previous prime is 21805783. The next prime is 21805807. The reversal of 21805795 is 59750812.

It is an interprime number because it is at equal distance from previous prime (21805783) and next prime (21805807).

It is not a de Polignac number, because 21805795 - 2⁹ = 21805283 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10666 + ... + 12544.

It is an arithmetic number, because the mean of its divisors is an integer number (1793520).

Almost surely, 2^21805795 is an apocalyptic number.

21805795 is a deficient number, since it is larger than the sum of its proper divisors (6890525).

21805795 is a wasteful number, since it uses less digits than its factorization.

21805795 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2106.

The product of its (nonzero) digits is 25200, while the sum is 37.

The square root of 21805795 is about 4669.6675470530. The cubic root of 21805795 is about 279.3769949326.

The spelling of 21805795 in words is "twenty-one million, eight hundred five thousand, seven hundred ninety-five".