306639 has 16 divisors (see below), whose sum is σ = 467040. Its totient is φ = 198720.

The previous prime is 306589. The next prime is 306643. The reversal of 306639 is 936603.

It is not a de Polignac number, because 306639 - 2⁷ = 306511 is a prime.

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

It is an Ulam number.

It is a d-powerful number, because it can be written as 3⁵ + 0 + 6³ + 6⁷ + 3⁹ + 9⁴ .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (306689) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 969 + ... + 1245.

It is an arithmetic number, because the mean of its divisors is an integer number (29190).

2³⁰⁶⁶³⁹ is an apocalyptic number.

306639 is a deficient number, since it is larger than the sum of its proper divisors (160401).

306639 is a wasteful number, since it uses less digits than its factorization.

306639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327 (or 321 counting only the distinct ones).

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

The square root of 306639 is about 553.7499435666. The cubic root of 306639 is about 67.4335147827.

The spelling of 306639 in words is "three hundred six thousand, six hundred thirty-nine".