19917958193 has 4 divisors (see below), whose sum is σ = 22763380800. Its totient is φ = 17072535588.

The previous prime is 19917958169. The next prime is 19917958223. The reversal of 19917958193 is 39185971991.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 19917958193 - 2⁶ = 19917958129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19917958133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1422711293 + ... + 1422711306.

It is an arithmetic number, because the mean of its divisors is an integer number (5690845200).

Almost surely, 2^19917958193 is an apocalyptic number.

It is an amenable number.

19917958193 is a deficient number, since it is larger than the sum of its proper divisors (2845422607).

19917958193 is an equidigital number, since it uses as much as digits as its factorization.

19917958193 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2845422606.

The product of its digits is 5511240, while the sum is 62.

The spelling of 19917958193 in words is "nineteen billion, nine hundred seventeen million, nine hundred fifty-eight thousand, one hundred ninety-three".