181255397 has 4 divisors (see below), whose sum is σ = 181900716. Its totient is φ = 180610080.

The previous prime is 181255351. The next prime is 181255429. The reversal of 181255397 is 793552181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 793552181 = 20323 ⋅39047.

It can be written as a sum of positive squares in 2 ways, for example, as 44809636 + 136445761 = 6694^2 + 11681^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-181255397 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 (181255897) 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, 322238 + ... + 322799.

It is an arithmetic number, because the mean of its divisors is an integer number (45475179).

Almost surely, 2^181255397 is an apocalyptic number.

It is an amenable number.

181255397 is a deficient number, since it is larger than the sum of its proper divisors (645319).

181255397 is an equidigital number, since it uses as much as digits as its factorization.

181255397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645318.

The product of its digits is 75600, while the sum is 41.

The square root of 181255397 is about 13463.1124558922. The cubic root of 181255397 is about 565.9312150300.

The spelling of 181255397 in words is "one hundred eighty-one million, two hundred fifty-five thousand, three hundred ninety-seven".