19693421388 has 36 divisors (see below), whose sum is σ = 49784874048. Its totient is φ = 6563909280.

The previous prime is 19693421351. The next prime is 19693421389. The reversal of 19693421388 is 88312439691.

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (19693421389) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 743818 + ... + 769838.

It is an arithmetic number, because the mean of its divisors is an integer number (1382913168).

Almost surely, 2^19693421388 is an apocalyptic number.

19693421388 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

19693421388 is an abundant number, since it is smaller than the sum of its proper divisors (30091452660).

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

19693421388 is a wasteful number, since it uses less digits than its factorization.

19693421388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47054 (or 47049 counting only the distinct ones).

The product of its digits is 2239488, while the sum is 54.

The spelling of 19693421388 in words is "nineteen billion, six hundred ninety-three million, four hundred twenty-one thousand, three hundred eighty-eight".