19955393917 has 16 divisors (see below), whose sum is σ = 21416659200. Its totient is φ = 18526510080.

The previous prime is 19955393897. The next prime is 19955393921. The reversal of 19955393917 is 71939355991.

It is a cyclic number.

It is not a de Polignac number, because 19955393917 - 2⁷ = 19955393789 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19955303917) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1566309 + ... + 1578997.

It is an arithmetic number, because the mean of its divisors is an integer number (1338541200).

Almost surely, 2^19955393917 is an apocalyptic number.

19955393917 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

19955393917 is a deficient number, since it is larger than the sum of its proper divisors (1461265283).

19955393917 is a wasteful number, since it uses less digits than its factorization.

19955393917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13956.

The product of its digits is 10333575, while the sum is 61.

The spelling of 19955393917 in words is "nineteen billion, nine hundred fifty-five million, three hundred ninety-three thousand, nine hundred seventeen".