198374231681 has 2 divisors, whose sum is σ = 198374231682. Its totient is φ = 198374231680.

The previous prime is 198374231669. The next prime is 198374231683. The reversal of 198374231681 is 186132473891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 179910857281 + 18463374400 = 424159^2 + 135880^2 .

It is a cyclic number.

It is not a de Polignac number, because 198374231681 - 2³⁴ = 181194362497 is a prime.

It is a super-2 number, since 2×198374231681² (a number of 23 digits) contains 22 as substring.

Together with 198374231683, 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 (198374231683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99187115840 + 99187115841.

It is an arithmetic number, because the mean of its divisors is an integer number (99187115841).

Almost surely, 2^198374231681 is an apocalyptic number.

It is an amenable number.

198374231681 is a deficient number, since it is larger than the sum of its proper divisors (1).

198374231681 is an equidigital number, since it uses as much as digits as its factorization.

198374231681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1741824, while the sum is 53.

The spelling of 198374231681 in words is "one hundred ninety-eight billion, three hundred seventy-four million, two hundred thirty-one thousand, six hundred eighty-one".