3655 has 8 divisors (see below), whose sum is σ = 4752. Its totient is φ = 2688.

The previous prime is 3643. The next prime is 3659. The reversal of 3655 is 5563.

3655 = 8² + 9² + ... + 22².

3655 is a nontrivial binomial coefficient, being equal to C(86, 2).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a 7-Lehmer number, since φ(3655) divides (3655-1)⁷.

It is a cyclic number.

It is not a de Polignac number, because 3655 - 2⁵ = 3623 is a prime.

It is a Duffinian number.

3655 is a lucky number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64 + ... + 106.

It is an arithmetic number, because the mean of its divisors is an integer number (594).

2³⁶⁵⁵ is an apocalyptic number.

3655 is the 85-th triangular number and also the 43-rd hexagonal number.

3655 is the 29-th centered nonagonal number.

3655 is a deficient number, since it is larger than the sum of its proper divisors (1097).

3655 is a wasteful number, since it uses less digits than its factorization.

3655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65.

The product of its digits is 450, while the sum is 19.

The square root of 3655 is about 60.4565960008. The cubic root of 3655 is about 15.4038445453.

It can be divided in two parts, 36 and 55, that added together give a triangular number (91 = T₁₃).

The spelling of 3655 in words is "three thousand, six hundred fifty-five".