1899656691973 has 2 divisors, whose sum is σ = 1899656691974. Its totient is φ = 1899656691972.

The previous prime is 1899656691953. The next prime is 1899656691997. The reversal of 1899656691973 is 3791966569981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1100352746529 + 799303945444 = 1048977^2 + 894038^2 .

It is a cyclic number.

It is not a de Polignac number, because 1899656691973 - 2²⁵ = 1899623137541 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1899656691893 and 1899656691902.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1899656691923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 949828345986 + 949828345987.

It is an arithmetic number, because the mean of its divisors is an integer number (949828345987).

Almost surely, 2^{1899656691973} is an apocalyptic number.

It is an amenable number.

1899656691973 is a deficient number, since it is larger than the sum of its proper divisors (1).

1899656691973 is an equidigital number, since it uses as much as digits as its factorization.

1899656691973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1190427840, while the sum is 79.

The spelling of 1899656691973 in words is "one trillion, eight hundred ninety-nine billion, six hundred fifty-six million, six hundred ninety-one thousand, nine hundred seventy-three".