21885285 has 16 divisors (see below), whose sum is σ = 36224640. Its totient is φ = 11269440.

The previous prime is 21885277. The next prime is 21885289. The reversal of 21885285 is 58258812.

It is not a de Polignac number, because 21885285 - 2³ = 21885277 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21885289) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24721 + ... + 25590.

It is an arithmetic number, because the mean of its divisors is an integer number (2264040).

Almost surely, 2^21885285 is an apocalyptic number.

It is an amenable number.

21885285 is a deficient number, since it is larger than the sum of its proper divisors (14339355).

21885285 is a wasteful number, since it uses less digits than its factorization.

21885285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50348.

The product of its digits is 51200, while the sum is 39.

The square root of 21885285 is about 4678.1711170072. The cubic root of 21885285 is about 279.7160599509.

The spelling of 21885285 in words is "twenty-one million, eight hundred eighty-five thousand, two hundred eighty-five".