643464 has 48 divisors (see below), whose sum is σ = 1812720. Its totient is φ = 213840.

The previous prime is 643463. The next prime is 643469. The reversal of 643464 is 464346.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (643463) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1779 + ... + 2109.

It is an arithmetic number, because the mean of its divisors is an integer number (37765).

2⁶⁴³⁴⁶⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (906360).

643464 is an abundant number, since it is smaller than the sum of its proper divisors (1169256).

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

643464 is a wasteful number, since it uses less digits than its factorization.

643464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352 (or 336 counting only the distinct ones).

The product of its digits is 6912, while the sum is 27.

The square root of 643464 is about 802.1620783857. The cubic root of 643464 is about 86.3325863030.

643464 divided by its sum of digits (27) gives a palindrome (23832).

The spelling of 643464 in words is "six hundred forty-three thousand, four hundred sixty-four".