309646 has 4 divisors (see below), whose sum is σ = 464472. Its totient is φ = 154822.

The previous prime is 309637. The next prime is 309667. The reversal of 309646 is 646903.

309646 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 646903 = 29 ⋅22307.

It is a d-powerful number, because it can be written as 3⁶ + 0 + 6² + 9² + 4⁹ + 6⁶ .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77410 + ... + 77413.

It is an arithmetic number, because the mean of its divisors is an integer number (116118).

2³⁰⁹⁶⁴⁶ is an apocalyptic number.

309646 is a deficient number, since it is larger than the sum of its proper divisors (154826).

309646 is a wasteful number, since it uses less digits than its factorization.

309646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154825.

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

The square root of 309646 is about 556.4584440908. The cubic root of 309646 is about 67.6532230270.

The spelling of 309646 in words is "three hundred nine thousand, six hundred forty-six".