81071200 has 144 divisors (see below), whose sum is σ = 233985024. Its totient is φ = 26841600.

The previous prime is 81071191. The next prime is 81071203. The reversal of 81071200 is 217018.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81071203) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 173367 + ... + 173833.

It is an arithmetic number, because the mean of its divisors is an integer number (1624896).

Almost surely, 2^81071200 is an apocalyptic number.

81071200 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81071200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116992512).

81071200 is an abundant number, since it is smaller than the sum of its proper divisors (152913824).

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

81071200 is a wasteful number, since it uses less digits than its factorization.

81071200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525 (or 512 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 19.

The square root of 81071200 is about 9003.9546866918. The cubic root of 81071200 is about 432.8016094824.

Adding to 81071200 its reverse (217018), we get a palindrome (81288218).

It can be divided in two parts, 810 and 71200, that added together give a triangular number (72010 = T₃₇₉).

The spelling of 81071200 in words is "eighty-one million, seventy-one thousand, two hundred".