19198256818 has 8 divisors (see below), whose sum is σ = 31012568748. Its totient is φ = 8860733904.

The previous prime is 19198256813. The next prime is 19198256843. The reversal of 19198256818 is 81865289191.

It can be written as a sum of positive squares in 2 ways, for example, as 19083488449 + 114768369 = 138143^2 + 10713^2 .

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

It is not an unprimeable number, because it can be changed into a prime (19198256813) 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, 369197221 + ... + 369197272.

Almost surely, 2^19198256818 is an apocalyptic number.

19198256818 is a deficient number, since it is larger than the sum of its proper divisors (11814311930).

19198256818 is a wasteful number, since it uses less digits than its factorization.

19198256818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 738394508.

The product of its digits is 2488320, while the sum is 58.

The spelling of 19198256818 in words is "nineteen billion, one hundred ninety-eight million, two hundred fifty-six thousand, eight hundred eighteen".