613666 has 8 divisors (see below), whose sum is σ = 974700. Its totient is φ = 288768.

The previous prime is 613661. The next prime is 613667. The reversal of 613666 is 666316.

It can be written as a sum of positive squares in 2 ways, for example, as 540225 + 73441 = 735^2 + 271^2 .

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

It is not an unprimeable number, because it can be changed into a prime (613661) 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, 8991 + ... + 9058.

2⁶¹³⁶⁶⁶ is an apocalyptic number.

613666 is a deficient number, since it is larger than the sum of its proper divisors (361034).

613666 is a wasteful number, since it uses less digits than its factorization.

613666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18068.

The product of its digits is 3888, while the sum is 28.

The square root of 613666 is about 783.3683680109. The cubic root of 613666 is about 84.9788182514.

Subtracting 613666 from its reverse (666316), we obtain a triangular number (52650 = T₃₂₄).

The spelling of 613666 in words is "six hundred thirteen thousand, six hundred sixty-six".