81331869399 has 32 divisors (see below), whose sum is σ = 120373344000. Its totient is φ = 48429461760.

The previous prime is 81331869383. The next prime is 81331869401. The reversal of 81331869399 is 99396813318.

It is not a de Polignac number, because 81331869399 - 2⁴ = 81331869383 is a prime.

It is a super-2 number, since 2×81331869399² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81331869349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3783987 + ... + 3805419.

It is an arithmetic number, because the mean of its divisors is an integer number (3761667000).

Almost surely, 2^81331869399 is an apocalyptic number.

81331869399 is a deficient number, since it is larger than the sum of its proper divisors (39041474601).

81331869399 is a wasteful number, since it uses less digits than its factorization.

81331869399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23455.

The product of its digits is 7558272, while the sum is 60.

The spelling of 81331869399 in words is "eighty-one billion, three hundred thirty-one million, eight hundred sixty-nine thousand, three hundred ninety-nine".