81288885 has 16 divisors (see below), whose sum is σ = 134547840. Its totient is φ = 41858880.

The previous prime is 81288881. The next prime is 81288899. The reversal of 81288885 is 58888218.

It is not a de Polignac number, because 81288885 - 2² = 81288881 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81288881) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 93001 + ... + 93870.

It is an arithmetic number, because the mean of its divisors is an integer number (8409240).

Almost surely, 2^81288885 is an apocalyptic number.

It is an amenable number.

81288885 is a deficient number, since it is larger than the sum of its proper divisors (53258955).

81288885 is a wasteful number, since it uses less digits than its factorization.

81288885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186908.

The product of its digits is 327680, while the sum is 48.

The square root of 81288885 is about 9016.0348823638. The cubic root of 81288885 is about 433.1886364357.

The spelling of 81288885 in words is "eighty-one million, two hundred eighty-eight thousand, eight hundred eighty-five".