1205663 has 2 divisors, whose sum is σ = 1205664. Its totient is φ = 1205662.

The previous prime is 1205653. The next prime is 1205669. The reversal of 1205663 is 3665021.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1205663 - 2⁴ = 1205647 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1205669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 602831 + 602832.

It is an arithmetic number, because the mean of its divisors is an integer number (602832).

2^1205663 is an apocalyptic number.

1205663 is a deficient number, since it is larger than the sum of its proper divisors (1).

1205663 is an equidigital number, since it uses as much as digits as its factorization.

1205663 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 1205663 is about 1098.0268667023. The cubic root of 1205663 is about 106.4327567468.

It can be divided in two parts, 12056 and 63, that multiplied together give a triangular number (759528 = T₁₂₃₂).

The spelling of 1205663 in words is "one million, two hundred five thousand, six hundred sixty-three".