19818319925 has 24 divisors (see below), whose sum is σ = 26090256456. Its totient is φ = 14881904640.

The previous prime is 19818319921. The next prime is 19818319979. The reversal of 19818319925 is 52991381891.

It can be written as a sum of positive squares in 12 ways, for example, as 7211746084 + 12606573841 = 84922^2 + 112279^2 .

It is not a de Polignac number, because 19818319925 - 2² = 19818319921 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19818319921) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 96017 + ... + 221033.

It is an arithmetic number, because the mean of its divisors is an integer number (1087094019).

Almost surely, 2^19818319925 is an apocalyptic number.

It is an amenable number.

19818319925 is a deficient number, since it is larger than the sum of its proper divisors (6271936531).

19818319925 is a wasteful number, since it uses less digits than its factorization.

19818319925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125417 (or 125412 counting only the distinct ones).

The product of its digits is 1399680, while the sum is 56.

The spelling of 19818319925 in words is "nineteen billion, eight hundred eighteen million, three hundred nineteen thousand, nine hundred twenty-five".