81013800 has 96 divisors (see below), whose sum is σ = 287035200. Its totient is φ = 18516480.

The previous prime is 81013783. The next prime is 81013811. The reversal of 81013800 is 831018.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5445 + ... + 13844.

It is an arithmetic number, because the mean of its divisors is an integer number (2989950).

Almost surely, 2^81013800 is an apocalyptic number.

It is an amenable number.

81013800 is an abundant number, since it is smaller than the sum of its proper divisors (206021400).

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

81013800 is a wasteful number, since it uses less digits than its factorization.

81013800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19315 (or 19306 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 21.

The square root of 81013800 is about 9000.7666340151. The cubic root of 81013800 is about 432.6994413563.

Adding to 81013800 its reverse (831018), we get a palindrome (81844818).

The spelling of 81013800 in words is "eighty-one million, thirteen thousand, eight hundred".