19855125617 has 2 divisors, whose sum is σ = 19855125618. Its totient is φ = 19855125616.

The previous prime is 19855125599. The next prime is 19855125683. The reversal of 19855125617 is 71652155891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19831398976 + 23726641 = 140824^2 + 4871^2 .

It is a cyclic number.

It is not a de Polignac number, because 19855125617 - 2⁶ = 19855125553 is a prime.

It is not a weakly prime, because it can be changed into another prime (19855124617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9927562808 + 9927562809.

It is an arithmetic number, because the mean of its divisors is an integer number (9927562809).

Almost surely, 2^19855125617 is an apocalyptic number.

It is an amenable number.

19855125617 is a deficient number, since it is larger than the sum of its proper divisors (1).

19855125617 is an equidigital number, since it uses as much as digits as its factorization.

19855125617 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 756000, while the sum is 50.

The spelling of 19855125617 in words is "nineteen billion, eight hundred fifty-five million, one hundred twenty-five thousand, six hundred seventeen".