81348157391 has 2 divisors, whose sum is σ = 81348157392. Its totient is φ = 81348157390.

The previous prime is 81348157351. The next prime is 81348157447. The reversal of 81348157391 is 19375184318.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81348157391 - 2⁶ = 81348157327 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81348157321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40674078695 + 40674078696.

It is an arithmetic number, because the mean of its divisors is an integer number (40674078696).

Almost surely, 2^81348157391 is an apocalyptic number.

81348157391 is a deficient number, since it is larger than the sum of its proper divisors (1).

81348157391 is an equidigital number, since it uses as much as digits as its factorization.

81348157391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 725760, while the sum is 50.

The spelling of 81348157391 in words is "eighty-one billion, three hundred forty-eight million, one hundred fifty-seven thousand, three hundred ninety-one".