181798749 has 54 divisors (see below), whose sum is σ = 301036190. Its totient is φ = 109699920.

The previous prime is 181798741. The next prime is 181798751. The reversal of 181798749 is 947897181.

It can be written as a sum of positive squares in only one way, i.e., 178623225 + 3175524 = 13365^2 + 1782^2 .

It is not a de Polignac number, because 181798749 - 2³ = 181798741 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 181798695 and 181798704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181798741) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 793767 + ... + 793995.

Almost surely, 2^181798749 is an apocalyptic number.

It is an amenable number.

181798749 is a deficient number, since it is larger than the sum of its proper divisors (119237441).

181798749 is an frugal number, since it uses more digits than its factorization.

181798749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275 (or 243 counting only the distinct ones).

The product of its digits is 1016064, while the sum is 54.

The square root of 181798749 is about 13483.2766418256. The cubic root of 181798749 is about 566.4961510406.

The spelling of 181798749 in words is "one hundred eighty-one million, seven hundred ninety-eight thousand, seven hundred forty-nine".