366561 has 18 divisors (see below), whose sum is σ = 575718. Its totient is φ = 224640.

The previous prime is 366547. The next prime is 366593. The reversal of 366561 is 165663.

366561 = 106² + 107² + ... + 131².

366561 is a `hidden beast` number, since 3 + 6 + 656 + 1 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 6561 + 360000 = 81^2 + 600^2 .

It is not a de Polignac number, because 366561 - 2⁶ = 366497 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (366511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1401 + ... + 1641.

2³⁶⁶⁵⁶¹ is an apocalyptic number.

It is an amenable number.

366561 is a deficient number, since it is larger than the sum of its proper divisors (209157).

366561 is a wasteful number, since it uses less digits than its factorization.

366561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273 (or 257 counting only the distinct ones).

The product of its digits is 3240, while the sum is 27.

The square root of 366561 is about 605.4428131541. The cubic root of 366561 is about 71.5674295022.

It can be divided in two parts, 36 and 6561, that multiplied together give a square (236196 = 486²).

The spelling of 366561 in words is "three hundred sixty-six thousand, five hundred sixty-one".