81698180231 has 2 divisors, whose sum is σ = 81698180232. Its totient is φ = 81698180230.

The previous prime is 81698180203. The next prime is 81698180233. The reversal of 81698180231 is 13208189618.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81698180231 - 2¹⁰ = 81698179207 is a prime.

It is a super-2 number, since 2×81698180231² (a number of 23 digits) contains 22 as substring.

Together with 81698180233, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81698180233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40849090115 + 40849090116.

It is an arithmetic number, because the mean of its divisors is an integer number (40849090116).

Almost surely, 2^81698180231 is an apocalyptic number.

81698180231 is a deficient number, since it is larger than the sum of its proper divisors (1).

81698180231 is an equidigital number, since it uses as much as digits as its factorization.

81698180231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 165888, while the sum is 47.

The spelling of 81698180231 in words is "eighty-one billion, six hundred ninety-eight million, one hundred eighty thousand, two hundred thirty-one".