642800 has 30 divisors (see below), whose sum is σ = 1545288. Its totient is φ = 256960.

The previous prime is 642799. The next prime is 642809. The reversal of 642800 is 8246.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 404 + ... + 1203.

2⁶⁴²⁸⁰⁰ is an apocalyptic number.

It is an amenable number.

642800 is an abundant number, since it is smaller than the sum of its proper divisors (902488).

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

642800 is a wasteful number, since it uses less digits than its factorization.

642800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1625 (or 1614 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 642800 is about 801.7480901131. The cubic root of 642800 is about 86.3028801258.

The spelling of 642800 in words is "six hundred forty-two thousand, eight hundred".