181730397 has 4 divisors (see below), whose sum is σ = 242307200. Its totient is φ = 121153596.

The previous prime is 181730389. The next prime is 181730399. The reversal of 181730397 is 793037181.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 181730397 - 2³ = 181730389 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 (181730399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30288397 + ... + 30288402.

It is an arithmetic number, because the mean of its divisors is an integer number (60576800).

Almost surely, 2^181730397 is an apocalyptic number.

It is an amenable number.

181730397 is a deficient number, since it is larger than the sum of its proper divisors (60576803).

181730397 is an equidigital number, since it uses as much as digits as its factorization.

181730397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60576802.

The product of its (nonzero) digits is 31752, while the sum is 39.

The square root of 181730397 is about 13480.7417080812. The cubic root of 181730397 is about 566.4251457872.

The spelling of 181730397 in words is "one hundred eighty-one million, seven hundred thirty thousand, three hundred ninety-seven".