81171360 has 72 divisors (see below), whose sum is σ = 277002180. Its totient is φ = 21645312.

The previous prime is 81171329. The next prime is 81171407. The reversal of 81171360 is 6317118.

It can be written as a sum of positive squares in 2 ways, for example, as 72386064 + 8785296 = 8508^2 + 2964^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26745 + ... + 29624.

Almost surely, 2^81171360 is an apocalyptic number.

81171360 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81171360 is an abundant number, since it is smaller than the sum of its proper divisors (195830820).

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

81171360 is a wasteful number, since it uses less digits than its factorization.

81171360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56390 (or 56379 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 81171360 is about 9009.5149702967. The cubic root of 81171360 is about 432.9797720906.

Adding to 81171360 its reverse (6317118), we get a palindrome (87488478).

The spelling of 81171360 in words is "eighty-one million, one hundred seventy-one thousand, three hundred sixty".