81318002 has 8 divisors (see below), whose sum is σ = 123976812. Its totient is φ = 39992400.

The previous prime is 81317981. The next prime is 81318007. The reversal of 81318002 is 20081318.

It can be written as a sum of positive squares in 2 ways, for example, as 54184321 + 27133681 = 7361^2 + 5209^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×81318002² = 13225234898544008, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81318007) 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, 333149 + ... + 333392.

Almost surely, 2^81318002 is an apocalyptic number.

81318002 is a deficient number, since it is larger than the sum of its proper divisors (42658810).

81318002 is a wasteful number, since it uses less digits than its factorization.

81318002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 666604.

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 81318002 is about 9017.6494720077. The cubic root of 81318002 is about 433.2403517792.

The spelling of 81318002 in words is "eighty-one million, three hundred eighteen thousand, two".