21500850 has 48 divisors (see below), whose sum is σ = 60942528. Its totient is φ = 4914240.

The previous prime is 21500833. The next prime is 21500893. The reversal of 21500850 is 5800512.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9189 + ... + 11288.

It is an arithmetic number, because the mean of its divisors is an integer number (1269636).

Almost surely, 2^21500850 is an apocalyptic number.

21500850 is an abundant number, since it is smaller than the sum of its proper divisors (39441678).

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

21500850 is a wasteful number, since it uses less digits than its factorization.

21500850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20499 (or 20494 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 21.

The square root of 21500850 is about 4636.9009046992. The cubic root of 21500850 is about 278.0685526988.

The spelling of 21500850 in words is "twenty-one million, five hundred thousand, eight hundred fifty".