181749109919 has 4 divisors (see below), whose sum is σ = 195729810696. Its totient is φ = 167768409144.

The previous prime is 181749109907. The next prime is 181749109957. The reversal of 181749109919 is 919901947181.

181749109919 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 181749109919 - 2¹² = 181749105823 is a prime.

It is a super-2 number, since 2×181749109919² (a number of 23 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 (181749109019) 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, 6990350369 + ... + 6990350394.

It is an arithmetic number, because the mean of its divisors is an integer number (48932452674).

Almost surely, 2^181749109919 is an apocalyptic number.

181749109919 is a deficient number, since it is larger than the sum of its proper divisors (13980700777).

181749109919 is a wasteful number, since it uses less digits than its factorization.

181749109919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13980700776.

The product of its (nonzero) digits is 1469664, while the sum is 59.

The spelling of 181749109919 in words is "one hundred eighty-one billion, seven hundred forty-nine million, one hundred nine thousand, nine hundred nineteen".