81219431462431 has 2 divisors, whose sum is σ = 81219431462432. Its totient is φ = 81219431462430.

The previous prime is 81219431462363. The next prime is 81219431462437. The reversal of 81219431462431 is 13426413491218.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81219431462431 - 2²³ = 81219423073823 is a prime.

It is a super-2 number, since 2×81219431462431² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81219431462437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40609715731215 + 40609715731216.

It is an arithmetic number, because the mean of its divisors is an integer number (40609715731216).

Almost surely, 2^{81219431462431} is an apocalyptic number.

81219431462431 is a deficient number, since it is larger than the sum of its proper divisors (1).

81219431462431 is an equidigital number, since it uses as much as digits as its factorization.

81219431462431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 995328, while the sum is 49.

The spelling of 81219431462431 in words is "eighty-one trillion, two hundred nineteen billion, four hundred thirty-one million, four hundred sixty-two thousand, four hundred thirty-one".