19139193921 has 8 divisors (see below), whose sum is σ = 25521491520. Its totient is φ = 12758179472.

The previous prime is 19139193917. The next prime is 19139193923. The reversal of 19139193921 is 12939193191.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 19139193921 - 2² = 19139193917 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19139193923) 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, 285426 + ... + 346043.

It is an arithmetic number, because the mean of its divisors is an integer number (3190186440).

Almost surely, 2^19139193921 is an apocalyptic number.

It is an amenable number.

19139193921 is a deficient number, since it is larger than the sum of its proper divisors (6382297599).

19139193921 is a wasteful number, since it uses less digits than its factorization.

19139193921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 641575.

The product of its digits is 118098, while the sum is 48.

The spelling of 19139193921 in words is "nineteen billion, one hundred thirty-nine million, one hundred ninety-three thousand, nine hundred twenty-one".