81232223197 has 2 divisors, whose sum is σ = 81232223198. Its totient is φ = 81232223196.

The previous prime is 81232223161. The next prime is 81232223227. The reversal of 81232223197 is 79132223218.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59013041476 + 22219181721 = 242926^2 + 149061^2 .

It is a cyclic number.

It is not a de Polignac number, because 81232223197 - 2¹¹ = 81232221149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81232923197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40616111598 + 40616111599.

It is an arithmetic number, because the mean of its divisors is an integer number (40616111599).

Almost surely, 2^81232223197 is an apocalyptic number.

It is an amenable number.

81232223197 is a deficient number, since it is larger than the sum of its proper divisors (1).

81232223197 is an equidigital number, since it uses as much as digits as its factorization.

81232223197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576, while the sum is 40.

The spelling of 81232223197 in words is "eighty-one billion, two hundred thirty-two million, two hundred twenty-three thousand, one hundred ninety-seven".