19819800061 has 2 divisors, whose sum is σ = 19819800062. Its totient is φ = 19819800060.

The previous prime is 19819799999. The next prime is 19819800067. The reversal of 19819800061 is 16000891891.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10693628100 + 9126171961 = 103410^2 + 95531^2 .

It is a cyclic number.

It is not a de Polignac number, because 19819800061 - 2¹³ = 19819791869 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19819799990 and 19819800017.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19819800067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9909900030 + 9909900031.

It is an arithmetic number, because the mean of its divisors is an integer number (9909900031).

Almost surely, 2^19819800061 is an apocalyptic number.

It is an amenable number.

19819800061 is a deficient number, since it is larger than the sum of its proper divisors (1).

19819800061 is an equidigital number, since it uses as much as digits as its factorization.

19819800061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 43.

The spelling of 19819800061 in words is "nineteen billion, eight hundred nineteen million, eight hundred thousand, sixty-one".