81027100 has 144 divisors (see below), whose sum is σ = 232485120. Its totient is φ = 23731200.

The previous prime is 81027071. The next prime is 81027109. The reversal of 81027100 is 172018.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81027109) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 130591 + ... + 131209.

It is an arithmetic number, because the mean of its divisors is an integer number (1614480).

Almost surely, 2^81027100 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81027100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116242560).

81027100 is an abundant number, since it is smaller than the sum of its proper divisors (151458020).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81027100 is a wasteful number, since it uses less digits than its factorization.

81027100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 668 (or 661 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 19.

The square root of 81027100 is about 9001.5054296490. The cubic root of 81027100 is about 432.7231187531.

Adding to 81027100 its reverse (172018), we get a palindrome (81199118).

The spelling of 81027100 in words is "eighty-one million, twenty-seven thousand, one hundred".