17981149903 has 4 divisors (see below), whose sum is σ = 17981731240. Its totient is φ = 17980568568.

The previous prime is 17981149897. The next prime is 17981149957. The reversal of 17981149903 is 30994118971.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 30994118971 = 61 ⋅508100311.

It is a cyclic number.

It is not a de Polignac number, because 17981149903 - 2¹⁷ = 17981018831 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17981179903) 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, 241500 + ... + 307057.

It is an arithmetic number, because the mean of its divisors is an integer number (4495432810).

Almost surely, 2^17981149903 is an apocalyptic number.

17981149903 is a deficient number, since it is larger than the sum of its proper divisors (581337).

17981149903 is an equidigital number, since it uses as much as digits as its factorization.

17981149903 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 581336.

The product of its (nonzero) digits is 489888, while the sum is 52.

The spelling of 17981149903 in words is "seventeen billion, nine hundred eighty-one million, one hundred forty-nine thousand, nine hundred three".