181902241 has 4 divisors (see below), whose sum is σ = 183061012. Its totient is φ = 180743472.

The previous prime is 181902229. The next prime is 181902263. The reversal of 181902241 is 142209181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 142209181 = 199 ⋅714619.

It can be written as a sum of positive squares in 2 ways, for example, as 36000000 + 145902241 = 6000^2 + 12079^2 .

It is a cyclic number.

It is not a de Polignac number, because 181902241 - 2⁵ = 181902209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181902271) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 579150 + ... + 579463.

It is an arithmetic number, because the mean of its divisors is an integer number (45765253).

Almost surely, 2^181902241 is an apocalyptic number.

It is an amenable number.

181902241 is a deficient number, since it is larger than the sum of its proper divisors (1158771).

181902241 is a wasteful number, since it uses less digits than its factorization.

181902241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1158770.

The product of its (nonzero) digits is 1152, while the sum is 28.

The square root of 181902241 is about 13487.1138869663. The cubic root of 181902241 is about 566.6036264743.

It can be divided in two parts, 18190224 and 1, that added together give a square (18190225 = 4265²).

The spelling of 181902241 in words is "one hundred eighty-one million, nine hundred two thousand, two hundred forty-one".