19938997813 has 8 divisors (see below), whose sum is σ = 22792278528. Its totient is φ = 17086930224.

The previous prime is 19938997807. The next prime is 19938997823. The reversal of 19938997813 is 31879983991.

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

It is not a de Polignac number, because 19938997813 - 2⁹ = 19938997301 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 (19938997823) 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, 267781 + ... + 334042.

It is an arithmetic number, because the mean of its divisors is an integer number (2849034816).

Almost surely, 2^19938997813 is an apocalyptic number.

It is an amenable number.

19938997813 is a deficient number, since it is larger than the sum of its proper divisors (2853280715).

19938997813 is an equidigital number, since it uses as much as digits as its factorization.

19938997813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 606563.

The product of its digits is 26453952, while the sum is 67.

The spelling of 19938997813 in words is "nineteen billion, nine hundred thirty-eight million, nine hundred ninety-seven thousand, eight hundred thirteen".