81150800 has 30 divisors (see below), whose sum is σ = 194965758. Its totient is φ = 32460160.

The previous prime is 81150793. The next prime is 81150803. The reversal of 81150800 is 805118.

It can be written as a sum of positive squares in 3 ways, for example, as 222784 + 80928016 = 472^2 + 8996^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81150803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 101039 + ... + 101838.

Almost surely, 2^81150800 is an apocalyptic number.

81150800 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81150800 is an abundant number, since it is smaller than the sum of its proper divisors (113814958).

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

81150800 is a wasteful number, since it uses less digits than its factorization.

81150800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202895 (or 202884 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 23.

The square root of 81150800 is about 9008.3738821166. The cubic root of 81150800 is about 432.9432123327.

Adding to 81150800 its reverse (805118), we get a palindrome (81955918).

The spelling of 81150800 in words is "eighty-one million, one hundred fifty thousand, eight hundred".