810193381 has 2 divisors, whose sum is σ = 810193382. Its totient is φ = 810193380.

The previous prime is 810193357. The next prime is 810193409. The reversal of 810193381 is 183391018.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 560268900 + 249924481 = 23670^2 + 15809^2 .

It is a cyclic number.

It is not a de Polignac number, because 810193381 - 2²¹ = 808096229 is a prime.

It is a super-2 number, since 2×810193381² = 1312826629232422322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (810193781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405096690 + 405096691.

It is an arithmetic number, because the mean of its divisors is an integer number (405096691).

Almost surely, 2^810193381 is an apocalyptic number.

It is an amenable number.

810193381 is a deficient number, since it is larger than the sum of its proper divisors (1).

810193381 is an equidigital number, since it uses as much as digits as its factorization.

810193381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 810193381 is about 28463.8960966344. The cubic root of 810193381 is about 932.2439285661.

The spelling of 810193381 in words is "eight hundred ten million, one hundred ninety-three thousand, three hundred eighty-one".