1890808911869 has 2 divisors, whose sum is σ = 1890808911870. Its totient is φ = 1890808911868.

The previous prime is 1890808911751. The next prime is 1890808911889. The reversal of 1890808911869 is 9681198080981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1890528751225 + 280160644 = 1374965^2 + 16738^2 .

It is a cyclic number.

It is not a de Polignac number, because 1890808911869 - 2²⁰ = 1890807863293 is a prime.

It is a super-2 number, since 2×1890808911869² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1890808911799 and 1890808911808.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1890808911889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 945404455934 + 945404455935.

It is an arithmetic number, because the mean of its divisors is an integer number (945404455935).

Almost surely, 2^{1890808911869} is an apocalyptic number.

It is an amenable number.

1890808911869 is a deficient number, since it is larger than the sum of its proper divisors (1).

1890808911869 is an equidigital number, since it uses as much as digits as its factorization.

1890808911869 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17915904, while the sum is 68.

The spelling of 1890808911869 in words is "one trillion, eight hundred ninety billion, eight hundred eight million, nine hundred eleven thousand, eight hundred sixty-nine".