181464561 has 12 divisors (see below), whose sum is σ = 262366260. Its totient is φ = 120860640.

The previous prime is 181464559. The next prime is 181464599. The reversal of 181464561 is 165464181.

181464561 is a `hidden beast` number, since 1 + 8 + 1 + 4 + 645 + 6 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 82083600 + 99380961 = 9060^2 + 9969^2 .

It is not a de Polignac number, because 181464561 - 2¹ = 181464559 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (181464541) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 891 + ... + 19071.

It is an arithmetic number, because the mean of its divisors is an integer number (21863855).

Almost surely, 2^181464561 is an apocalyptic number.

It is an amenable number.

181464561 is a deficient number, since it is larger than the sum of its proper divisors (80901699).

181464561 is a wasteful number, since it uses less digits than its factorization.

181464561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19296 (or 19293 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 181464561 is about 13470.8782564464. The cubic root of 181464561 is about 566.1488213007.

The spelling of 181464561 in words is "one hundred eighty-one million, four hundred sixty-four thousand, five hundred sixty-one".