81061850 has 12 divisors (see below), whose sum is σ = 150775134. Its totient is φ = 32424720.

The previous prime is 81061781. The next prime is 81061853. The reversal of 81061850 is 5816018.

It can be written as a sum of positive squares in 3 ways, for example, as 35485849 + 45576001 = 5957^2 + 6751^2 .

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (81061853) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 810569 + ... + 810668.

Almost surely, 2^81061850 is an apocalyptic number.

81061850 is a deficient number, since it is larger than the sum of its proper divisors (69713284).

81061850 is a wasteful number, since it uses less digits than its factorization.

81061850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1621249 (or 1621244 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 29.

The square root of 81061850 is about 9003.4354554248. The cubic root of 81061850 is about 432.7849704021.

Adding to 81061850 its reverse (5816018), we get a palindrome (86877868).

The spelling of 81061850 in words is "eighty-one million, sixty-one thousand, eight hundred fifty".