19998766125 has 192 divisors, whose sum is σ = 40874258880. Its totient is φ = 9338112000.

The previous prime is 19998766121. The next prime is 19998766157. The reversal of 19998766125 is 52166789991.

19998766125 is a `hidden beast` number, since 1 + 9 + 9 + 9 + 8 + 7 + 6 + 612 + 5 = 666.

It can be written as a sum of positive squares in 32 ways, for example, as 14166236484 + 5832529641 = 119022^2 + 76371^2 .

It is not a de Polignac number, because 19998766125 - 2² = 19998766121 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 (19998766121) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 25871239 + ... + 25872011.

It is an arithmetic number, because the mean of its divisors is an integer number (212886765).

Almost surely, 2^19998766125 is an apocalyptic number.

19998766125 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19998766125 is an abundant number, since it is smaller than the sum of its proper divisors (20875492755).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19998766125 is a wasteful number, since it uses less digits than its factorization.

19998766125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 897 (or 884 counting only the distinct ones).

The product of its digits is 14696640, while the sum is 63.

The spelling of 19998766125 in words is "nineteen billion, nine hundred ninety-eight million, seven hundred sixty-six thousand, one hundred twenty-five".