81373944845 has 8 divisors (see below), whose sum is σ = 97665630720. Its totient is φ = 65087891280.

The previous prime is 81373944833. The next prime is 81373944887. The reversal of 81373944845 is 54844937318.

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

It is not a de Polignac number, because 81373944845 - 2¹⁸ = 81373682701 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1376225 + ... + 1434134.

It is an arithmetic number, because the mean of its divisors is an integer number (12208203840).

Almost surely, 2^81373944845 is an apocalyptic number.

It is an amenable number.

81373944845 is a deficient number, since it is larger than the sum of its proper divisors (16291685875).

81373944845 is a wasteful number, since it uses less digits than its factorization.

81373944845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2816155.

The product of its digits is 11612160, while the sum is 56.

The spelling of 81373944845 in words is "eighty-one billion, three hundred seventy-three million, nine hundred forty-four thousand, eight hundred forty-five".