1891905400013 has 2 divisors, whose sum is σ = 1891905400014. Its totient is φ = 1891905400012.

The previous prime is 1891905399977. The next prime is 1891905400019. The reversal of 1891905400013 is 3100045091981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 959651425924 + 932253974089 = 979618^2 + 965533^2 .

It is a cyclic number.

It is not a de Polignac number, because 1891905400013 - 2¹⁶ = 1891905334477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1891905400019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 945952700006 + 945952700007.

It is an arithmetic number, because the mean of its divisors is an integer number (945952700007).

Almost surely, 2^{1891905400013} is an apocalyptic number.

It is an amenable number.

1891905400013 is a deficient number, since it is larger than the sum of its proper divisors (1).

1891905400013 is an equidigital number, since it uses as much as digits as its factorization.

1891905400013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38880, while the sum is 41.

The spelling of 1891905400013 in words is "one trillion, eight hundred ninety-one billion, nine hundred five million, four hundred thousand, thirteen".