17981900138 has 8 divisors (see below), whose sum is σ = 27902948580. Its totient is φ = 8680917280.

The previous prime is 17981900119. The next prime is 17981900141. The reversal of 17981900138 is 83100918971.

It can be written as a sum of positive squares in 2 ways, for example, as 17181179929 + 800720209 = 131077^2 + 28297^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 17981900092 and 17981900101.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 155016323 + ... + 155016438.

Almost surely, 2^17981900138 is an apocalyptic number.

17981900138 is a deficient number, since it is larger than the sum of its proper divisors (9921048442).

17981900138 is a wasteful number, since it uses less digits than its factorization.

17981900138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310032792.

The product of its (nonzero) digits is 108864, while the sum is 47.

The spelling of 17981900138 in words is "seventeen billion, nine hundred eighty-one million, nine hundred thousand, one hundred thirty-eight".