81081836751 has 8 divisors (see below), whose sum is σ = 111596506624. Its totient is φ = 52310862360.

The previous prime is 81081836743. The next prime is 81081836807. The reversal of 81081836751 is 15763818018.

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

It is not a de Polignac number, because 81081836751 - 2³ = 81081836743 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81081836751.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81081836851) 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 7 ways as a sum of consecutive naturals, for example, 435923761 + ... + 435923946.

It is an arithmetic number, because the mean of its divisors is an integer number (13949563328).

Almost surely, 2^81081836751 is an apocalyptic number.

81081836751 is a deficient number, since it is larger than the sum of its proper divisors (30514669873).

81081836751 is a wasteful number, since it uses less digits than its factorization.

81081836751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 871847741.

The product of its (nonzero) digits is 322560, while the sum is 48.

The spelling of 81081836751 in words is "eighty-one billion, eighty-one million, eight hundred thirty-six thousand, seven hundred fifty-one".