21289850 has 24 divisors (see below), whose sum is σ = 39774240. Its totient is φ = 8478320.

The previous prime is 21289843. The next prime is 21289867. The reversal of 21289850 is 5898212.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21289850.

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, 12341 + ... + 13959.

It is an arithmetic number, because the mean of its divisors is an integer number (1657260).

Almost surely, 2^21289850 is an apocalyptic number.

21289850 is a deficient number, since it is larger than the sum of its proper divisors (18484390).

21289850 is a wasteful number, since it uses less digits than its factorization.

21289850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1894 (or 1889 counting only the distinct ones).

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

The square root of 21289850 is about 4614.0925435019. The cubic root of 21289850 is about 277.1559461957.

The spelling of 21289850 in words is "twenty-one million, two hundred eighty-nine thousand, eight hundred fifty".