642628 has 24 divisors (see below), whose sum is σ = 1310400. Its totient is φ = 270048.

The previous prime is 642623. The next prime is 642673. The reversal of 642628 is 826246.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 642596 and 642605.

It is not an unprimeable number, because it can be changed into a prime (642623) 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, 1458 + ... + 1846.

It is an arithmetic number, because the mean of its divisors is an integer number (54600).

2⁶⁴²⁶²⁸ is an apocalyptic number.

It is an amenable number.

642628 is an abundant number, since it is smaller than the sum of its proper divisors (667772).

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

642628 is a wasteful number, since it uses less digits than its factorization.

642628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459 (or 457 counting only the distinct ones).

The product of its digits is 4608, while the sum is 28.

The square root of 642628 is about 801.6408173241. The cubic root of 642628 is about 86.2951818165.

The spelling of 642628 in words is "six hundred forty-two thousand, six hundred twenty-eight".