21384809850 has 24 divisors (see below), whose sum is σ = 53034328800. Its totient is φ = 5702615920.

The previous prime is 21384809819. The next prime is 21384809869. The reversal of 21384809850 is 5890848312.

It is a self number, because there is not a number n which added to its sum of digits gives 21384809850.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 71282550 + ... + 71282849.

It is an arithmetic number, because the mean of its divisors is an integer number (2209763700).

Almost surely, 2^21384809850 is an apocalyptic number.

21384809850 is an abundant number, since it is smaller than the sum of its proper divisors (31649518950).

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

21384809850 is a wasteful number, since it uses less digits than its factorization.

21384809850 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142565414 (or 142565409 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 48.

The spelling of 21384809850 in words is "twenty-one billion, three hundred eighty-four million, eight hundred nine thousand, eight hundred fifty".