642980 has 24 divisors (see below), whose sum is σ = 1454712. Its totient is φ = 237312.

The previous prime is 642977. The next prime is 642997. The reversal of 642980 is 89246.

It can be written as a sum of positive squares in 4 ways, for example, as 40804 + 602176 = 202^2 + 776^2 .

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 977 + ... + 1496.

It is an arithmetic number, because the mean of its divisors is an integer number (60613).

2⁶⁴²⁹⁸⁰ is an apocalyptic number.

It is an amenable number.

642980 is an abundant number, since it is smaller than the sum of its proper divisors (811732).

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

642980 is a wasteful number, since it uses less digits than its factorization.

642980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2495 (or 2493 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 642980 is about 801.8603369665. The cubic root of 642980 is about 86.3109350255.

The spelling of 642980 in words is "six hundred forty-two thousand, nine hundred eighty".