81180288 has 96 divisors (see below), whose sum is σ = 267003360. Its totient is φ = 23192064.

The previous prime is 81180277. The next prime is 81180313. The reversal of 81180288 is 88208118.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 3031 + ... + 13097.

It is an arithmetic number, because the mean of its divisors is an integer number (2781285).

Almost surely, 2^81180288 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81180288, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133501680).

81180288 is an abundant number, since it is smaller than the sum of its proper divisors (185823072).

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

81180288 is a wasteful number, since it uses less digits than its factorization.

81180288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10094 (or 10079 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 36.

The square root of 81180288 is about 9010.0104328463. The cubic root of 81180288 is about 432.9956459230.

The spelling of 81180288 in words is "eighty-one million, one hundred eighty thousand, two hundred eighty-eight".