81709059 has 8 divisors (see below), whose sum is σ = 109510672. Its totient is φ = 54190080.

The previous prime is 81709051. The next prime is 81709079. The reversal of 81709059 is 95090718.

It is a happy number.

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

It is not a de Polignac number, because 81709059 - 2³ = 81709051 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81709051) 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, 69982 + ... + 71139.

It is an arithmetic number, because the mean of its divisors is an integer number (13688834).

Almost surely, 2^81709059 is an apocalyptic number.

81709059 is a deficient number, since it is larger than the sum of its proper divisors (27801613).

81709059 is a wasteful number, since it uses less digits than its factorization.

81709059 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141317.

The product of its (nonzero) digits is 22680, while the sum is 39.

The square root of 81709059 is about 9039.3063340059. The cubic root of 81709059 is about 433.9337235185.

The spelling of 81709059 in words is "eighty-one million, seven hundred nine thousand, fifty-nine".