36661 has 4 divisors (see below), whose sum is σ = 37324. Its totient is φ = 36000.

The previous prime is 36653. The next prime is 36671. The reversal of 36661 is 16663.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16663 = 19 ⋅877.

It can be written as a sum of positive squares in 2 ways, for example, as 14161 + 22500 = 119^2 + 150^2 .

It is a 3-Lehmer number, since φ(36661) divides (36661-1)³.

It is a cyclic number.

It is not a de Polignac number, because 36661 - 2³ = 36653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (36671) 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, 240 + ... + 361.

It is an arithmetic number, because the mean of its divisors is an integer number (9331).

2³⁶⁶⁶¹ is an apocalyptic number.

It is an amenable number.

36661 is a deficient number, since it is larger than the sum of its proper divisors (663).

36661 is an equidigital number, since it uses as much as digits as its factorization.

36661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 662.

The product of its digits is 648, while the sum is 22.

The square root of 36661 is about 191.4706243788. The cubic root of 36661 is about 33.2201382636.

The spelling of 36661 in words is "thirty-six thousand, six hundred sixty-one".