81058209 has 8 divisors (see below), whose sum is σ = 108122112. Its totient is φ = 54016560.

The previous prime is 81058207. The next prime is 81058217. The reversal of 81058209 is 90285018.

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 81058209 - 2¹ = 81058207 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81058209.

It is not an unprimeable number, because it can be changed into a prime (81058207) 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, 6979 + ... + 14519.

It is an arithmetic number, because the mean of its divisors is an integer number (13515264).

Almost surely, 2^81058209 is an apocalyptic number.

It is an amenable number.

81058209 is a deficient number, since it is larger than the sum of its proper divisors (27063903).

81058209 is a wasteful number, since it uses less digits than its factorization.

81058209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11127.

The product of its (nonzero) digits is 5760, while the sum is 33.

The square root of 81058209 is about 9003.2332525599. The cubic root of 81058209 is about 432.7784906023.

The spelling of 81058209 in words is "eighty-one million, fifty-eight thousand, two hundred nine".