81100359 has 20 divisors (see below), whose sum is σ = 121663080. Its totient is φ = 53838000.

The previous prime is 81100343. The next prime is 81100361. The reversal of 81100359 is 95300118.

It is not a de Polignac number, because 81100359 - 2⁴ = 81100343 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81100339) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 18337 + ... + 22325.

It is an arithmetic number, because the mean of its divisors is an integer number (6083154).

Almost surely, 2^81100359 is an apocalyptic number.

81100359 is a deficient number, since it is larger than the sum of its proper divisors (40562721).

81100359 is a wasteful number, since it uses less digits than its factorization.

81100359 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4252 (or 4243 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 81100359 is about 9005.5737740579. The cubic root of 81100359 is about 432.8534920638.

The spelling of 81100359 in words is "eighty-one million, one hundred thousand, three hundred fifty-nine".