81756323 has 8 divisors (see below), whose sum is σ = 89449920. Its totient is φ = 74106280.

The previous prime is 81756319. The next prime is 81756341. The reversal of 81756323 is 32365718.

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 81756323 - 2² = 81756319 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81756313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6893 + ... + 14526.

It is an arithmetic number, because the mean of its divisors is an integer number (11181240).

Almost surely, 2^81756323 is an apocalyptic number.

81756323 is a deficient number, since it is larger than the sum of its proper divisors (7693597).

81756323 is a wasteful number, since it uses less digits than its factorization.

81756323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21777.

The product of its digits is 30240, while the sum is 35.

The square root of 81756323 is about 9041.9203159506. The cubic root of 81756323 is about 434.0173759740.

The spelling of 81756323 in words is "eighty-one million, seven hundred fifty-six thousand, three hundred twenty-three".