81292288 has 88 divisors (see below), whose sum is σ = 202800384. Its totient is φ = 31641600.

The previous prime is 81292273. The next prime is 81292331. The reversal of 81292288 is 88229218.

It is a tau number, because it is divible by the number of its divisors (88).

It is a self number, because there is not a number n which added to its sum of digits gives 81292288.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 78333 + ... + 79363.

Almost surely, 2^81292288 is an apocalyptic number.

81292288 is a gapful number since it is divisible by the number (88) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81292288, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101400192).

81292288 is an abundant number, since it is smaller than the sum of its proper divisors (121508096).

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

81292288 is a wasteful number, since it uses less digits than its factorization.

81292288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1069 (or 1051 counting only the distinct ones).

The product of its digits is 36864, while the sum is 40.

The square root of 81292288 is about 9016.2235997118. The cubic root of 81292288 is about 433.1946812160.

The spelling of 81292288 in words is "eighty-one million, two hundred ninety-two thousand, two hundred eighty-eight".