81186550129 has 8 divisors (see below), whose sum is σ = 83734858368. Its totient is φ = 78672447600.

The previous prime is 81186550121. The next prime is 81186550139. The reversal of 81186550129 is 92105568118.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81186550129 - 2³ = 81186550121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81186550121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8546607 + ... + 8556100.

It is an arithmetic number, because the mean of its divisors is an integer number (10466857296).

Almost surely, 2^81186550129 is an apocalyptic number.

It is an amenable number.

81186550129 is a deficient number, since it is larger than the sum of its proper divisors (2548308239).

81186550129 is a wasteful number, since it uses less digits than its factorization.

81186550129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17102855.

The product of its (nonzero) digits is 172800, while the sum is 46.

The spelling of 81186550129 in words is "eighty-one billion, one hundred eighty-six million, five hundred fifty thousand, one hundred twenty-nine".