19905374863937 has 6 divisors (see below), whose sum is σ = 21145155997638. Its totient is φ = 18734470459904.

The previous prime is 19905374863909. The next prime is 19905374863939. The reversal of 19905374863937 is 73936847350991.

It is a Cunningham number, because it is equal to 4461544²+1.

It can be written as a sum of positive squares in 3 ways, for example, as 6177690366016 + 13727684497921 = 2485496^2 + 3705089^2 .

It is not a de Polignac number, because 19905374863937 - 2⁸ = 19905374863681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19905374863939) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 34438364528 + ... + 34438365105.

It is an arithmetic number, because the mean of its divisors is an integer number (3524192666273).

Almost surely, 2^{19905374863937} is an apocalyptic number.

19905374863937 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

19905374863937 is a deficient number, since it is larger than the sum of its proper divisors (1239781133701).

19905374863937 is an equidigital number, since it uses as much as digits as its factorization.

19905374863937 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68876729667 (or 68876729650 counting only the distinct ones).

The product of its (nonzero) digits is 925888320, while the sum is 74.

The spelling of 19905374863937 in words is "nineteen trillion, nine hundred five billion, three hundred seventy-four million, eight hundred sixty-three thousand, nine hundred thirty-seven".