18729103581 has 10 divisors (see below), whose sum is σ = 27978043742. Its totient is φ = 12486069000.

The previous prime is 18729103577. The next prime is 18729103583. The reversal of 18729103581 is 18530192781.

18729103581 is a `hidden beast` number, since 1 + 8 + 7 + 291 + 0 + 358 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 16344344025 + 2384759556 = 127845^2 + 48834^2 .

It is not a de Polignac number, because 18729103581 - 2² = 18729103577 is a prime.

It is a super-2 number, since 2×18729103581² (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 (18729103583) 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 9 ways as a sum of consecutive naturals, for example, 115611670 + ... + 115611831.

Almost surely, 2^18729103581 is an apocalyptic number.

It is an amenable number.

18729103581 is a deficient number, since it is larger than the sum of its proper divisors (9248940161).

18729103581 is an equidigital number, since it uses as much as digits as its factorization.

18729103581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231223513 (or 231223504 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 45.

The spelling of 18729103581 in words is "eighteen billion, seven hundred twenty-nine million, one hundred three thousand, five hundred eighty-one".