17978369519 has 4 divisors (see below), whose sum is σ = 19612766760. Its totient is φ = 16343972280.

The previous prime is 17978369483. The next prime is 17978369527. The reversal of 17978369519 is 91596387971.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 17978369519 - 2¹² = 17978365423 is a prime.

It is a super-2 number, since 2×17978369519² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17978369569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 817198604 + ... + 817198625.

It is an arithmetic number, because the mean of its divisors is an integer number (4903191690).

Almost surely, 2^17978369519 is an apocalyptic number.

17978369519 is a deficient number, since it is larger than the sum of its proper divisors (1634397241).

17978369519 is a wasteful number, since it uses less digits than its factorization.

17978369519 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1634397240.

The product of its digits is 25719120, while the sum is 65.

The spelling of 17978369519 in words is "seventeen billion, nine hundred seventy-eight million, three hundred sixty-nine thousand, five hundred nineteen".