81288504 has 96 divisors (see below), whose sum is σ = 241853040. Its totient is φ = 24460800.

The previous prime is 81288481. The next prime is 81288511. The reversal of 81288504 is 40588218.

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

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 155764 + ... + 156284.

Almost surely, 2^81288504 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 81288504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120926520).

81288504 is an abundant number, since it is smaller than the sum of its proper divisors (160564536).

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

81288504 is a wasteful number, since it uses less digits than its factorization.

81288504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 741 (or 734 counting only the distinct ones).

The product of its (nonzero) digits is 20480, while the sum is 36.

The square root of 81288504 is about 9016.0137533169. The cubic root of 81288504 is about 433.1879596513.

The spelling of 81288504 in words is "eighty-one million, two hundred eighty-eight thousand, five hundred four".