643662 has 12 divisors (see below), whose sum is σ = 1394640. Its totient is φ = 214548.

The previous prime is 643661. The next prime is 643681. The reversal of 643662 is 266346.

643662 is nontrivially palindromic in base 15.

643662 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643661) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 17862 + ... + 17897.

It is an arithmetic number, because the mean of its divisors is an integer number (116220).

2⁶⁴³⁶⁶² is an apocalyptic number.

643662 is an abundant number, since it is smaller than the sum of its proper divisors (750978).

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

643662 is a wasteful number, since it uses less digits than its factorization.

643662 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35767 (or 35764 counting only the distinct ones).

The product of its digits is 5184, while the sum is 27.

The square root of 643662 is about 802.2854853480. The cubic root of 643662 is about 86.3414405145.

Adding to 643662 its product of digits (5184), we get a palindrome (648846).

The spelling of 643662 in words is "six hundred forty-three thousand, six hundred sixty-two".