81327280 has 40 divisors (see below), whose sum is σ = 191920752. Its totient is φ = 32043264.

The previous prime is 81327271. The next prime is 81327293. The reversal of 81327280 is 8272318.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×81327280² = 13228252944396800, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2227 + ... + 12946.

Almost surely, 2^81327280 is an apocalyptic number.

81327280 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81327280 is an abundant number, since it is smaller than the sum of its proper divisors (110593472).

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

81327280 is a wasteful number, since it uses less digits than its factorization.

81327280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15253 (or 15247 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 81327280 is about 9018.1638929441. The cubic root of 81327280 is about 433.2568280453.

Adding to 81327280 its reverse (8272318), we get a palindrome (89599598).

The spelling of 81327280 in words is "eighty-one million, three hundred twenty-seven thousand, two hundred eighty".