21892805 has 16 divisors (see below), whose sum is σ = 29329344. Its totient is φ = 15550080.

The previous prime is 21892799. The next prime is 21892813. The reversal of 21892805 is 50829812.

It is not a de Polignac number, because 21892805 - 2²² = 17698501 is a prime.

It is a congruent number.

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, 2264 + ... + 6993.

It is an arithmetic number, because the mean of its divisors is an integer number (1833084).

Almost surely, 2^21892805 is an apocalyptic number.

It is an amenable number.

21892805 is a deficient number, since it is larger than the sum of its proper divisors (7436539).

21892805 is a wasteful number, since it uses less digits than its factorization.

21892805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9316.

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 21892805 is about 4678.9747808681. The cubic root of 21892805 is about 279.7480940154.

It can be divided in two parts, 2189 and 2805, that added together give a palindrome (4994).

The spelling of 21892805 in words is "twenty-one million, eight hundred ninety-two thousand, eight hundred five".