1938893900891 has 2 divisors, whose sum is σ = 1938893900892. Its totient is φ = 1938893900890.

The previous prime is 1938893900869. The next prime is 1938893900893. The reversal of 1938893900891 is 1980093988391.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1938893900891 is a prime.

Together with 1938893900893, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1938893900893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 969446950445 + 969446950446.

It is an arithmetic number, because the mean of its divisors is an integer number (969446950446).

Almost surely, 2^{1938893900891} is an apocalyptic number.

1938893900891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1938893900891 is an equidigital number, since it uses as much as digits as its factorization.

1938893900891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30233088, while the sum is 68.

The spelling of 1938893900891 in words is "one trillion, nine hundred thirty-eight billion, eight hundred ninety-three million, nine hundred thousand, eight hundred ninety-one".