81346742431 has 2 divisors, whose sum is σ = 81346742432. Its totient is φ = 81346742430.

The previous prime is 81346742419. The next prime is 81346742461. The reversal of 81346742431 is 13424764318.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81346742431 - 2¹¹ = 81346740383 is a prime.

It is a super-2 number, since 2×81346742431² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81346742461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40673371215 + 40673371216.

It is an arithmetic number, because the mean of its divisors is an integer number (40673371216).

Almost surely, 2^81346742431 is an apocalyptic number.

81346742431 is a deficient number, since it is larger than the sum of its proper divisors (1).

81346742431 is an equidigital number, since it uses as much as digits as its factorization.

81346742431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 387072, while the sum is 43.

The spelling of 81346742431 in words is "eighty-one billion, three hundred forty-six million, seven hundred forty-two thousand, four hundred thirty-one".