81247874218 has 24 divisors (see below), whose sum is σ = 141801820452. Its totient is φ = 34812517824.

The previous prime is 81247874209. The next prime is 81247874231.

81247874218 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 2 ways, for example, as 80455620609 + 792253609 = 283647^2 + 28147^2 .

It is a super-2 number, since 2×81247874218² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 343780 + ... + 529792.

Almost surely, 2^81247874218 is an apocalyptic number.

81247874218 is a deficient number, since it is larger than the sum of its proper divisors (60553946234).

81247874218 is a wasteful number, since it uses less digits than its factorization.

81247874218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190486 (or 190479 counting only the distinct ones).

The product of its digits is 1605632, while the sum is 52.

The spelling of 81247874218 in words is "eighty-one billion, two hundred forty-seven million, eight hundred seventy-four thousand, two hundred eighteen".