81170800 has 60 divisors (see below), whose sum is σ = 195944056. Its totient is φ = 32313600.

The previous prime is 81170779. The next prime is 81170807. The reversal of 81170800 is 807118.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81170807) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 122470 + ... + 123130.

Almost surely, 2^81170800 is an apocalyptic number.

81170800 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 81170800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97972028).

81170800 is an abundant number, since it is smaller than the sum of its proper divisors (114773256).

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

81170800 is a wasteful number, since it uses less digits than its factorization.

81170800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 986 (or 975 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 25.

The square root of 81170800 is about 9009.4838919885. The cubic root of 81170800 is about 432.9787763813.

Adding to 81170800 its reverse (807118), we get a palindrome (81977918).

The spelling of 81170800 in words is "eighty-one million, one hundred seventy thousand, eight hundred".