81881520763 has 8 divisors (see below), whose sum is σ = 94487414528. Its totient is φ = 69502760424.

The previous prime is 81881520761. The next prime is 81881520821. The reversal of 81881520763 is 36702518818.

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 81881520763 - 2¹ = 81881520761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81881520761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56782581 + ... + 56784022.

It is an arithmetic number, because the mean of its divisors is an integer number (11810926816).

Almost surely, 2^81881520763 is an apocalyptic number.

81881520763 is a deficient number, since it is larger than the sum of its proper divisors (12605893765).

81881520763 is a wasteful number, since it uses less digits than its factorization.

81881520763 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113566713.

The product of its (nonzero) digits is 645120, while the sum is 49.

The spelling of 81881520763 in words is "eighty-one billion, eight hundred eighty-one million, five hundred twenty thousand, seven hundred sixty-three".