642988 has 24 divisors (see below), whose sum is σ = 1219680. Its totient is φ = 295680.

The previous prime is 642977. The next prime is 642997. The reversal of 642988 is 889246.

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2548 + ... + 2788.

It is an arithmetic number, because the mean of its divisors is an integer number (50820).

2⁶⁴²⁹⁸⁸ is an apocalyptic number.

It is an amenable number.

642988 is a deficient number, since it is larger than the sum of its proper divisors (576692).

642988 is a wasteful number, since it uses less digits than its factorization.

642988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297 (or 295 counting only the distinct ones).

The product of its digits is 27648, while the sum is 37.

The square root of 642988 is about 801.8653253508. The cubic root of 642988 is about 86.3112929862.

The spelling of 642988 in words is "six hundred forty-two thousand, nine hundred eighty-eight".