81100839 has 8 divisors (see below), whose sum is σ = 108387072. Its totient is φ = 53940920.

The previous prime is 81100837. The next prime is 81100853. The reversal of 81100839 is 93800118.

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 81100839 - 2¹ = 81100837 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81100837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30069 + ... + 32654.

It is an arithmetic number, because the mean of its divisors is an integer number (13548384).

Almost surely, 2^81100839 is an apocalyptic number.

81100839 is a deficient number, since it is larger than the sum of its proper divisors (27286233).

81100839 is a wasteful number, since it uses less digits than its factorization.

81100839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63157.

The product of its (nonzero) digits is 1728, while the sum is 30.

The square root of 81100839 is about 9005.6004241805. The cubic root of 81100839 is about 432.8543460233.

The spelling of 81100839 in words is "eighty-one million, one hundred thousand, eight hundred thirty-nine".