642309 has 8 divisors (see below), whose sum is σ = 860832. Its totient is φ = 426000.

The previous prime is 642281. The next prime is 642359. The reversal of 642309 is 903246.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 642309 - 2¹¹ = 640261 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642359) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 327 + ... + 1179.

It is an arithmetic number, because the mean of its divisors is an integer number (107604).

2⁶⁴²³⁰⁹ is an apocalyptic number.

It is an amenable number.

642309 is a deficient number, since it is larger than the sum of its proper divisors (218523).

642309 is a wasteful number, since it uses less digits than its factorization.

642309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1107.

The product of its (nonzero) digits is 1296, while the sum is 24.

The square root of 642309 is about 801.4418257116. The cubic root of 642309 is about 86.2809005013.

The spelling of 642309 in words is "six hundred forty-two thousand, three hundred nine".