642818 has 16 divisors (see below), whose sum is σ = 1071360. Its totient is φ = 286800.

The previous prime is 642809. The next prime is 642833. The reversal of 642818 is 818246.

It is a super-2 number, since 2×642818² = 826429962248, which contains 22 as substring.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 642818.

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, 1103 + ... + 1581.

It is an arithmetic number, because the mean of its divisors is an integer number (66960).

2⁶⁴²⁸¹⁸ is an apocalyptic number.

642818 is a deficient number, since it is larger than the sum of its proper divisors (428542).

642818 is a wasteful number, since it uses less digits than its factorization.

642818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 553.

The product of its digits is 3072, while the sum is 29.

The square root of 642818 is about 801.7593155056. The cubic root of 642818 is about 86.3036856834.

It can be divided in two parts, 6428 and 18, that added together give a palindrome (6446).

The spelling of 642818 in words is "six hundred forty-two thousand, eight hundred eighteen".