81816060 has 96 divisors (see below), whose sum is σ = 241823232. Its totient is φ = 20627200.

The previous prime is 81816043. The next prime is 81816061. The reversal of 81816060 is 6061818.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81816061) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 139087 + ... + 139673.

It is an arithmetic number, because the mean of its divisors is an integer number (2518992).

Almost surely, 2^81816060 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 81816060, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120911616).

81816060 is an abundant number, since it is smaller than the sum of its proper divisors (160007172).

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

81816060 is a wasteful number, since it uses less digits than its factorization.

81816060 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 723 (or 721 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 81816060 is about 9045.2230486594. The cubic root of 81816060 is about 434.1230582541.

Adding to 81816060 its reverse (6061818), we get a palindrome (87877878).

It can be divided in two parts, 8181 and 6060, that added together give a palindrome (14241).

The spelling of 81816060 in words is "eighty-one million, eight hundred sixteen thousand, sixty".