81388373 has 8 divisors (see below), whose sum is σ = 89618400. Its totient is φ = 73296880.

The previous prime is 81388319. The next prime is 81388387. The reversal of 81388373 is 37388318.

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 81388373 - 2⁶ = 81388309 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81388373.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81388303) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33398 + ... + 35751.

It is an arithmetic number, because the mean of its divisors is an integer number (11202300).

Almost surely, 2^81388373 is an apocalyptic number.

It is an amenable number.

81388373 is a deficient number, since it is larger than the sum of its proper divisors (8230027).

81388373 is a wasteful number, since it uses less digits than its factorization.

81388373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69267.

The product of its digits is 96768, while the sum is 41.

The square root of 81388373 is about 9021.5504764979. The cubic root of 81388373 is about 433.3652883075.

The spelling of 81388373 in words is "eighty-one million, three hundred eighty-eight thousand, three hundred seventy-three".