19668643974 has 24 divisors (see below), whose sum is σ = 48703309200. Its totient is φ = 5619612528.

The previous prime is 19668643963. The next prime is 19668644011. The reversal of 19668643974 is 47934686691.

19668643974 is a `hidden beast` number, since 196 + 6 + 8 + 6 + 439 + 7 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

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, 78050049 + ... + 78050300.

It is an arithmetic number, because the mean of its divisors is an integer number (2029304550).

Almost surely, 2^19668643974 is an apocalyptic number.

19668643974 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

19668643974 is an abundant number, since it is smaller than the sum of its proper divisors (29034665226).

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

19668643974 is a wasteful number, since it uses less digits than its factorization.

19668643974 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156100364 (or 156100361 counting only the distinct ones).

The product of its digits is 47029248, while the sum is 63.

The spelling of 19668643974 in words is "nineteen billion, six hundred sixty-eight million, six hundred forty-three thousand, nine hundred seventy-four".