81196254039 has 4 divisors (see below), whose sum is σ = 108261672056. Its totient is φ = 54130836024.

The previous prime is 81196254017. The next prime is 81196254047. The reversal of 81196254039 is 93045269118.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 81196254039 - 2²⁰ = 81195205463 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81196254089) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13532709004 + ... + 13532709009.

It is an arithmetic number, because the mean of its divisors is an integer number (27065418014).

Almost surely, 2^81196254039 is an apocalyptic number.

81196254039 is a deficient number, since it is larger than the sum of its proper divisors (27065418017).

81196254039 is a wasteful number, since it uses less digits than its factorization.

81196254039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27065418016.

The product of its (nonzero) digits is 466560, while the sum is 48.

The spelling of 81196254039 in words is "eighty-one billion, one hundred ninety-six million, two hundred fifty-four thousand, thirty-nine".