12398447818 has 4 divisors (see below), whose sum is σ = 18597671730. Its totient is φ = 6199223908.

The previous prime is 12398447779. The next prime is 12398447821. The reversal of 12398447818 is 81874489321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81874489321 = 122609 ⋅667769.

It can be written as a sum of positive squares in only one way, i.e., 7703046289 + 4695401529 = 87767^2 + 68523^2 .

It is a super-2 number, since 2×12398447818² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3099611953 + ... + 3099611956.

Almost surely, 2^12398447818 is an apocalyptic number.

12398447818 is a deficient number, since it is larger than the sum of its proper divisors (6199223912).

12398447818 is an equidigital number, since it uses as much as digits as its factorization.

12398447818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6199223911.

The product of its digits is 3096576, while the sum is 55.

The spelling of 12398447818 in words is "twelve billion, three hundred ninety-eight million, four hundred forty-seven thousand, eight hundred eighteen".