21017990050 has 48 divisors (see below), whose sum is σ = 39864234240. Its totient is φ = 8241704640.

The previous prime is 21017990047. The next prime is 21017990083. The reversal of 21017990050 is 5009971012.

It is a junction number, because it is equal to n+sod(n) for n = 21017989988 and 21017990015.

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, 4181839 + ... + 4186861.

It is an arithmetic number, because the mean of its divisors is an integer number (830504880).

Almost surely, 2^21017990050 is an apocalyptic number.

21017990050 is a deficient number, since it is larger than the sum of its proper divisors (18846244190).

21017990050 is a wasteful number, since it uses less digits than its factorization.

21017990050 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6667 (or 6662 counting only the distinct ones).

The product of its (nonzero) digits is 5670, while the sum is 34.

The spelling of 21017990050 in words is "twenty-one billion, seventeen million, nine hundred ninety thousand, fifty".