181542149 has 2 divisors, whose sum is σ = 181542150. Its totient is φ = 181542148.

The previous prime is 181542143. The next prime is 181542181. The reversal of 181542149 is 941245181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 114597025 + 66945124 = 10705^2 + 8182^2 .

It is a cyclic number.

It is not a de Polignac number, because 181542149 - 2²⁴ = 164764933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (181542143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90771074 + 90771075.

It is an arithmetic number, because the mean of its divisors is an integer number (90771075).

Almost surely, 2^181542149 is an apocalyptic number.

It is an amenable number.

181542149 is a deficient number, since it is larger than the sum of its proper divisors (1).

181542149 is an equidigital number, since it uses as much as digits as its factorization.

181542149 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11520, while the sum is 35.

The square root of 181542149 is about 13473.7577906091. The cubic root of 181542149 is about 566.2294983863.

The spelling of 181542149 in words is "one hundred eighty-one million, five hundred forty-two thousand, one hundred forty-nine".