838194577921 has 2 divisors, whose sum is σ = 838194577922. Its totient is φ = 838194577920.

The previous prime is 838194577889. The next prime is 838194577939. The reversal of 838194577921 is 129775491838.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 730872817921 + 107321760000 = 854911^2 + 327600^2 .

It is a cyclic number.

It is not a de Polignac number, because 838194577921 - 2⁵ = 838194577889 is a prime.

It is not a weakly prime, because it can be changed into another prime (838194577951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 419097288960 + 419097288961.

It is an arithmetic number, because the mean of its divisors is an integer number (419097288961).

Almost surely, 2^838194577921 is an apocalyptic number.

It is an amenable number.

838194577921 is a deficient number, since it is larger than the sum of its proper divisors (1).

838194577921 is an equidigital number, since it uses as much as digits as its factorization.

838194577921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30481920, while the sum is 64.

The spelling of 838194577921 in words is "eight hundred thirty-eight billion, one hundred ninety-four million, five hundred seventy-seven thousand, nine hundred twenty-one".