81120089 has 4 divisors (see below), whose sum is σ = 81864420. Its totient is φ = 80375760.

The previous prime is 81120079. The next prime is 81120113. The reversal of 81120089 is 98002118.

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

It can be written as a sum of positive squares in 2 ways, for example, as 42680089 + 38440000 = 6533^2 + 6200^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81120089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81120079) 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, 372002 + ... + 372219.

It is an arithmetic number, because the mean of its divisors is an integer number (20466105).

Almost surely, 2^81120089 is an apocalyptic number.

It is an amenable number.

81120089 is a deficient number, since it is larger than the sum of its proper divisors (744331).

81120089 is a wasteful number, since it uses less digits than its factorization.

81120089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 744330.

The product of its (nonzero) digits is 1152, while the sum is 29.

The square root of 81120089 is about 9006.6691401428. The cubic root of 81120089 is about 432.8885905806. Note that the first 3 decimals are identical.

The spelling of 81120089 in words is "eighty-one million, one hundred twenty thousand, eighty-nine".