245666 has 4 divisors (see below), whose sum is σ = 368502. Its totient is φ = 122832.

The previous prime is 245653. The next prime is 245671. The reversal of 245666 is 666542.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 666542 = 2 ⋅333271.

It can be written as a sum of positive squares in only one way, i.e., 172225 + 73441 = 415^2 + 271^2 .

It is a Curzon number.

It is a plaindrome in base 10.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 245666.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61415 + ... + 61418.

2²⁴⁵⁶⁶⁶ is an apocalyptic number.

245666 is a deficient number, since it is larger than the sum of its proper divisors (122836).

245666 is a wasteful number, since it uses less digits than its factorization.

245666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122835.

The product of its digits is 8640, while the sum is 29.

The square root of 245666 is about 495.6470518423. The cubic root of 245666 is about 62.6298951822.

The spelling of 245666 in words is "two hundred forty-five thousand, six hundred sixty-six".