81392095849 has 9 divisors (see below), whose sum is σ = 84111482109. Its totient is φ = 78757985580.

The previous prime is 81392095847. The next prime is 81392095853. The reversal of 81392095849 is 94859029318.

The square root of 81392095849 is 285293.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 81392095849 - 2¹ = 81392095847 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81392095793 and 81392095802.

It is not an unprimeable number, because it can be changed into a prime (81392095847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 8839482 + ... + 8848684.

Almost surely, 2^81392095849 is an apocalyptic number.

81392095849 is the 285293-rd square number.

81392095849 is the 142647-th centered octagonal number.

It is an amenable number.

81392095849 is a deficient number, since it is larger than the sum of its proper divisors (2719386260).

81392095849 is an frugal number, since it uses more digits than its factorization.

81392095849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18468 (or 9234 counting only the distinct ones).

The product of its (nonzero) digits is 5598720, while the sum is 58.

The spelling of 81392095849 in words is "eighty-one billion, three hundred ninety-two million, ninety-five thousand, eight hundred forty-nine".