21095850 has 24 divisors (see below), whose sum is σ = 52318080. Its totient is φ = 5625520.

The previous prime is 21095849. The next prime is 21095869. The reversal of 21095850 is 5859012.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a Curzon number.

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, 70170 + ... + 70469.

It is an arithmetic number, because the mean of its divisors is an integer number (2179920).

Almost surely, 2^21095850 is an apocalyptic number.

21095850 is an abundant number, since it is smaller than the sum of its proper divisors (31222230).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21095850 is a wasteful number, since it uses less digits than its factorization.

21095850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140654 (or 140649 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 30.

The square root of 21095850 is about 4593.0218810713. The cubic root of 21095850 is about 276.3115312388.

It can be divided in two parts, 21095 and 850, that added together give a triangular number (21945 = T₂₀₉).

The spelling of 21095850 in words is "twenty-one million, ninety-five thousand, eight hundred fifty".