642306 has 32 divisors (see below), whose sum is σ = 1507968. Its totient is φ = 178560.

The previous prime is 642281. The next prime is 642359. The reversal of 642306 is 603246.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1536 + ... + 1908.

It is an arithmetic number, because the mean of its divisors is an integer number (47124).

2⁶⁴²³⁰⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642306, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (753984).

642306 is an abundant number, since it is smaller than the sum of its proper divisors (865662).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

642306 is a wasteful number, since it uses less digits than its factorization.

642306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426.

The product of its (nonzero) digits is 864, while the sum is 21.

The square root of 642306 is about 801.4399540826. The cubic root of 642306 is about 86.2807661718.

Subtracting from 642306 its reverse (603246), we obtain a triangular number (39060 = T₂₇₉).

The spelling of 642306 in words is "six hundred forty-two thousand, three hundred six".