81883913991 has 64 divisors (see below), whose sum is σ = 129388285440. Its totient is φ = 45507338240.

The previous prime is 81883913987. The next prime is 81883913999. The reversal of 81883913991 is 19931938818.

It is a cyclic number.

It is not a de Polignac number, because 81883913991 - 2² = 81883913987 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81883913999) 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 63 ways as a sum of consecutive naturals, for example, 3729241 + ... + 3751133.

It is an arithmetic number, because the mean of its divisors is an integer number (2021691960).

Almost surely, 2^81883913991 is an apocalyptic number.

81883913991 is a deficient number, since it is larger than the sum of its proper divisors (47504371449).

81883913991 is a wasteful number, since it uses less digits than its factorization.

81883913991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22096.

The product of its digits is 3359232, while the sum is 60.

The spelling of 81883913991 in words is "eighty-one billion, eight hundred eighty-three million, nine hundred thirteen thousand, nine hundred ninety-one".