181530731 has 8 divisors (see below), whose sum is σ = 191393280. Its totient is φ = 171699048.

The previous prime is 181530721. The next prime is 181530733. The reversal of 181530731 is 137035181.

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

It is a de Polignac number, because none of the positive numbers 2^k-181530731 is a prime.

It is a super-2 number, since 2×181530731² = 65906812594788722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 181530694 and 181530703.

It is not an unprimeable number, because it can be changed into a prime (181530733) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4910 + ... + 19676.

It is an arithmetic number, because the mean of its divisors is an integer number (23924160).

Almost surely, 2^181530731 is an apocalyptic number.

181530731 is a deficient number, since it is larger than the sum of its proper divisors (9862549).

181530731 is a wasteful number, since it uses less digits than its factorization.

181530731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15433.

The product of its (nonzero) digits is 2520, while the sum is 29.

The square root of 181530731 is about 13473.3340714168. The cubic root of 181530731 is about 566.2176272331.

The spelling of 181530731 in words is "one hundred eighty-one million, five hundred thirty thousand, seven hundred thirty-one".