81041280 has 64 divisors (see below), whose sum is σ = 258325200. Its totient is φ = 21610496.

The previous prime is 81041267. The next prime is 81041287. The reversal of 81041280 is 8214018.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 81041280.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81041287) 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 7 ways as a sum of consecutive naturals, for example, 19185 + ... + 23024.

Almost surely, 2^81041280 is an apocalyptic number.

81041280 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81041280 is an abundant number, since it is smaller than the sum of its proper divisors (177283920).

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

81041280 is a wasteful number, since it uses less digits than its factorization.

81041280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42231 (or 42219 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 24.

The square root of 81041280 is about 9002.2930412201. The cubic root of 81041280 is about 432.7483599210.

Adding to 81041280 its reverse (8214018), we get a palindrome (89255298).

The spelling of 81041280 in words is "eighty-one million, forty-one thousand, two hundred eighty".