81692568847 has 2 divisors, whose sum is σ = 81692568848. Its totient is φ = 81692568846.

The previous prime is 81692568829. The next prime is 81692568877. The reversal of 81692568847 is 74886529618.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81692568847 - 2⁷ = 81692568719 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81692568877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40846284423 + 40846284424.

It is an arithmetic number, because the mean of its divisors is an integer number (40846284424).

Almost surely, 2^81692568847 is an apocalyptic number.

81692568847 is a deficient number, since it is larger than the sum of its proper divisors (1).

81692568847 is an equidigital number, since it uses as much as digits as its factorization.

81692568847 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46448640, while the sum is 64.

The spelling of 81692568847 in words is "eighty-one billion, six hundred ninety-two million, five hundred sixty-eight thousand, eight hundred forty-seven".