642885 has 8 divisors (see below), whose sum is σ = 1028640. Its totient is φ = 342864.

The previous prime is 642881. The next prime is 642899. The reversal of 642885 is 588246.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 642885 - 2² = 642881 is a prime.

It is a super-2 number, since 2×642885² = 826602246450, which contains 22 as substring.

642885 is a lucky number.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642881) 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 7 ways as a sum of consecutive naturals, for example, 21415 + ... + 21444.

It is an arithmetic number, because the mean of its divisors is an integer number (128580).

2⁶⁴²⁸⁸⁵ is an apocalyptic number.

It is an amenable number.

642885 is a deficient number, since it is larger than the sum of its proper divisors (385755).

642885 is a wasteful number, since it uses less digits than its factorization.

642885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42867.

The product of its digits is 15360, while the sum is 33.

The square root of 642885 is about 801.8010975298. The cubic root of 642885 is about 86.3066840158.

The spelling of 642885 in words is "six hundred forty-two thousand, eight hundred eighty-five".