19928215666 has 16 divisors (see below), whose sum is σ = 30481409088. Its totient is φ = 9769662000.

The previous prime is 19928215663. The next prime is 19928215717. The reversal of 19928215666 is 66651282991.

It is not an unprimeable number, because it can be changed into a prime (19928215661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 458100 + ... + 499711.

It is an arithmetic number, because the mean of its divisors is an integer number (1905088068).

Almost surely, 2^19928215666 is an apocalyptic number.

19928215666 is a deficient number, since it is larger than the sum of its proper divisors (10553193422).

19928215666 is a wasteful number, since it uses less digits than its factorization.

19928215666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 958017.

The product of its digits is 2799360, while the sum is 55.

The spelling of 19928215666 in words is "nineteen billion, nine hundred twenty-eight million, two hundred fifteen thousand, six hundred sixty-six".