81318284 has 18 divisors (see below), whose sum is σ = 144965940. Its totient is φ = 39901912.

The previous prime is 81318283. The next prime is 81318299. The reversal of 81318284 is 48281318.

It is a super-2 number, since 2×81318284² = 13225326625409312, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81318283) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 138239 + ... + 138825.

Almost surely, 2^81318284 is an apocalyptic number.

It is an amenable number.

81318284 is a deficient number, since it is larger than the sum of its proper divisors (63647656).

81318284 is an equidigital number, since it uses as much as digits as its factorization.

81318284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1237 (or 648 counting only the distinct ones).

The product of its digits is 12288, while the sum is 35.

The square root of 81318284 is about 9017.6651079977. The cubic root of 81318284 is about 433.2408525853.

The spelling of 81318284 in words is "eighty-one million, three hundred eighteen thousand, two hundred eighty-four".