21855850 has 24 divisors (see below), whose sum is σ = 42056460. Its totient is φ = 8440320.

The previous prime is 21855839. The next prime is 21855877. The reversal of 21855850 is 5855812.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 7935489 + 13920361 = 2817^2 + 3731^2 .

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6087 + ... + 8986.

Almost surely, 2^21855850 is an apocalyptic number.

21855850 is a deficient number, since it is larger than the sum of its proper divisors (20200610).

21855850 is a wasteful number, since it uses less digits than its factorization.

21855850 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15114 (or 15109 counting only the distinct ones).

The product of its (nonzero) digits is 16000, while the sum is 34.

The square root of 21855850 is about 4675.0240641092. The cubic root of 21855850 is about 279.5906006720.

The spelling of 21855850 in words is "twenty-one million, eight hundred fifty-five thousand, eight hundred fifty".