19889955650 has 24 divisors (see below), whose sum is σ = 37158313680. Its totient is φ = 7920929360.

The previous prime is 19889955619. The next prime is 19889955661. The reversal of 19889955650 is 5655998891.

It is a super-2 number, since 2×19889955650² (a number of 21 digits) contains 22 as substring.

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, 864860 + ... + 887559.

It is an arithmetic number, because the mean of its divisors is an integer number (1548263070).

Almost surely, 2^19889955650 is an apocalyptic number.

19889955650 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19889955650 is a deficient number, since it is larger than the sum of its proper divisors (17268358030).

19889955650 is a wasteful number, since it uses less digits than its factorization.

19889955650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1752658 (or 1752653 counting only the distinct ones).

The product of its (nonzero) digits is 34992000, while the sum is 65.

The spelling of 19889955650 in words is "nineteen billion, eight hundred eighty-nine million, nine hundred fifty-five thousand, six hundred fifty".