21085284850 has 24 divisors (see below), whose sum is σ = 44821291968. Its totient is φ = 7229240400.

The previous prime is 21085284793. The next prime is 21085284851. The reversal of 21085284850 is 5848258012.

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21085284797 and 21085284806.

It is not an unprimeable number, because it can be changed into a prime (21085284851) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30121486 + ... + 30122185.

It is an arithmetic number, because the mean of its divisors is an integer number (1867553832).

Almost surely, 2^21085284850 is an apocalyptic number.

21085284850 is an abundant number, since it is smaller than the sum of its proper divisors (23736007118).

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

21085284850 is a wasteful number, since it uses less digits than its factorization.

21085284850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60243690 (or 60243685 counting only the distinct ones).

The product of its (nonzero) digits is 204800, while the sum is 43.

The spelling of 21085284850 in words is "twenty-one billion, eighty-five million, two hundred eighty-four thousand, eight hundred fifty".