81381853399 has 96 divisors (see below), whose sum is σ = 111016319040. Its totient is φ = 58783334400.

The previous prime is 81381853369. The next prime is 81381853411. The reversal of 81381853399 is 99335818318.

It is not a de Polignac number, because 81381853399 - 2⁹ = 81381852887 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81381853369) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 302534637 + ... + 302534905.

It is an arithmetic number, because the mean of its divisors is an integer number (1156419990).

Almost surely, 2^81381853399 is an apocalyptic number.

81381853399 is a deficient number, since it is larger than the sum of its proper divisors (29634465641).

81381853399 is a wasteful number, since it uses less digits than its factorization.

81381853399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 689 (or 682 counting only the distinct ones).

The product of its digits is 5598720, while the sum is 58.

The spelling of 81381853399 in words is "eighty-one billion, three hundred eighty-one million, eight hundred fifty-three thousand, three hundred ninety-nine".