81659323 has 4 divisors (see below), whose sum is σ = 81954400. Its totient is φ = 81364248.

The previous prime is 81659299. The next prime is 81659371. The reversal of 81659323 is 32395618.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81659323 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81659023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 147123 + ... + 147676.

It is an arithmetic number, because the mean of its divisors is an integer number (20488600).

Almost surely, 2^81659323 is an apocalyptic number.

81659323 is a deficient number, since it is larger than the sum of its proper divisors (295077).

81659323 is a wasteful number, since it uses less digits than its factorization.

81659323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295076.

The product of its digits is 38880, while the sum is 37.

The square root of 81659323 is about 9036.5548191775. The cubic root of 81659323 is about 433.8456610344.

The spelling of 81659323 in words is "eighty-one million, six hundred fifty-nine thousand, three hundred twenty-three".