81288760 has 32 divisors (see below), whose sum is σ = 209028960. Its totient is φ = 27870336.

The previous prime is 81288749. The next prime is 81288761. The reversal of 81288760 is 6788218.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81288761) by changing a digit.

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, 144879 + ... + 145438.

It is an arithmetic number, because the mean of its divisors is an integer number (6532155).

Almost surely, 2^81288760 is an apocalyptic number.

It is an amenable number.

81288760 is an abundant number, since it is smaller than the sum of its proper divisors (127740200).

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

81288760 is a wasteful number, since it uses less digits than its factorization.

81288760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290335 (or 290331 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 40.

The square root of 81288760 is about 9016.0279502672. The cubic root of 81288760 is about 433.1884143938.

The spelling of 81288760 in words is "eighty-one million, two hundred eighty-eight thousand, seven hundred sixty".