309663 has 10 divisors (see below), whose sum is σ = 462704. Its totient is φ = 206388.

The previous prime is 309637. The next prime is 309667. The reversal of 309663 is 366903.

It is not a de Polignac number, because 309663 - 2⁶ = 309599 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a d-powerful number, because it can be written as 3⁷ + 0 + 6⁵ + 9² + 6⁷ + 3⁹ .

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (309667) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1831 + ... + 1992.

2³⁰⁹⁶⁶³ is an apocalyptic number.

309663 is a deficient number, since it is larger than the sum of its proper divisors (153041).

309663 is an equidigital number, since it uses as much as digits as its factorization.

309663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3835 (or 3826 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 27.

The square root of 309663 is about 556.4737190560. The cubic root of 309663 is about 67.6544610900.

The spelling of 309663 in words is "three hundred nine thousand, six hundred sixty-three".