19965815425 has 6 divisors (see below), whose sum is σ = 24757611158. Its totient is φ = 15972652320.

The previous prime is 19965815417. The next prime is 19965815437. The reversal of 19965815425 is 52451856991.

It can be written as a sum of positive squares in 3 ways, for example, as 364695409 + 19601120016 = 19097^2 + 140004^2 .

It is not a de Polignac number, because 19965815425 - 2³ = 19965815417 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 399316284 + ... + 399316333.

Almost surely, 2^19965815425 is an apocalyptic number.

It is an amenable number.

19965815425 is a deficient number, since it is larger than the sum of its proper divisors (4791795733).

19965815425 is an equidigital number, since it uses as much as digits as its factorization.

19965815425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 798632627 (or 798632622 counting only the distinct ones).

The product of its digits is 3888000, while the sum is 55.

The spelling of 19965815425 in words is "nineteen billion, nine hundred sixty-five million, eight hundred fifteen thousand, four hundred twenty-five".