181294145 has 4 divisors (see below), whose sum is σ = 217552980. Its totient is φ = 145035312.

The previous prime is 181294123. The next prime is 181294147. The reversal of 181294145 is 541492181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 541492181 = 61 ⋅8876921.

It can be written as a sum of positive squares in 2 ways, for example, as 105534529 + 75759616 = 10273^2 + 8704^2 .

It is a cyclic number.

It is not a de Polignac number, because 181294145 - 2²² = 177099841 is a prime.

It is a super-2 number, since 2×181294145² = 65735134022562050, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (181294147) 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, 18129410 + ... + 18129419.

It is an arithmetic number, because the mean of its divisors is an integer number (54388245).

Almost surely, 2^181294145 is an apocalyptic number.

It is an amenable number.

181294145 is a deficient number, since it is larger than the sum of its proper divisors (36258835).

181294145 is an equidigital number, since it uses as much as digits as its factorization.

181294145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36258834.

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

The square root of 181294145 is about 13464.5514221603. The cubic root of 181294145 is about 565.9715396045.

The spelling of 181294145 in words is "one hundred eighty-one million, two hundred ninety-four thousand, one hundred forty-five".