645342 has 16 divisors (see below), whose sum is σ = 1313280. Its totient is φ = 211352.

The previous prime is 645329. The next prime is 645347. The reversal of 645342 is 243546.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645347) 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, 558 + ... + 1265.

It is an arithmetic number, because the mean of its divisors is an integer number (82080).

2⁶⁴⁵³⁴² is an apocalyptic number.

645342 is an abundant number, since it is smaller than the sum of its proper divisors (667938).

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

645342 is a wasteful number, since it uses less digits than its factorization.

645342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1887.

The product of its digits is 2880, while the sum is 24.

The square root of 645342 is about 803.3318118934. The cubic root of 645342 is about 86.4164941932.

Adding to 645342 its reverse (243546), we get a palindrome (888888).

The spelling of 645342 in words is "six hundred forty-five thousand, three hundred forty-two".