19661998256 has 20 divisors (see below), whose sum is σ = 38139291072. Its totient is φ = 9819600576.

The previous prime is 19661998241. The next prime is 19661998277. The reversal of 19661998256 is 65289916691.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 698171 + ... + 725786.

Almost surely, 2^19661998256 is an apocalyptic number.

19661998256 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

19661998256 is a deficient number, since it is larger than the sum of its proper divisors (18477292816).

19661998256 is a wasteful number, since it uses less digits than its factorization.

19661998256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1424828 (or 1424822 counting only the distinct ones).

The product of its digits is 12597120, while the sum is 62.

The spelling of 19661998256 in words is "nineteen billion, six hundred sixty-one million, nine hundred ninety-eight thousand, two hundred fifty-six".