81061860 has 96 divisors (see below), whose sum is σ = 249080832. Its totient is φ = 19534720.

The previous prime is 81061853. The next prime is 81061889. The reversal of 81061860 is 6816018.

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

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 173347 + ... + 173813.

It is an arithmetic number, because the mean of its divisors is an integer number (2594592).

Almost surely, 2^81061860 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 81061860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124540416).

81061860 is an abundant number, since it is smaller than the sum of its proper divisors (168018972).

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

81061860 is a wasteful number, since it uses less digits than its factorization.

81061860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 753 (or 751 counting only the distinct ones).

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

The square root of 81061860 is about 9003.4360107683. The cubic root of 81061860 is about 432.7849881985.

Adding to 81061860 its reverse (6816018), we get a palindrome (87877878).

The spelling of 81061860 in words is "eighty-one million, sixty-one thousand, eight hundred sixty".