81636288 has 28 divisors (see below), whose sum is σ = 215996520. Its totient is φ = 27212032.

The previous prime is 81636283. The next prime is 81636337. The reversal of 81636288 is 88263618.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81636281) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 212403 + ... + 212786.

Almost surely, 2^81636288 is an apocalyptic number.

It is an amenable number.

81636288 is an abundant number, since it is smaller than the sum of its proper divisors (134360232).

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

81636288 is a wasteful number, since it uses less digits than its factorization.

81636288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425204 (or 425194 counting only the distinct ones).

The product of its digits is 110592, while the sum is 42.

The square root of 81636288 is about 9035.2801838128. The cubic root of 81636288 is about 433.8048631835.

The spelling of 81636288 in words is "eighty-one million, six hundred thirty-six thousand, two hundred eighty-eight".