643020 has 48 divisors (see below), whose sum is σ = 2059008. Its totient is φ = 146880.

The previous prime is 643009. The next prime is 643021. The reversal of 643020 is 20346.

643020 = 280² + 281² + ... + 287².

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 346 + ... + 1185.

It is an arithmetic number, because the mean of its divisors is an integer number (42896).

2⁶⁴³⁰²⁰ is an apocalyptic number.

643020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

643020 is an abundant number, since it is smaller than the sum of its proper divisors (1415988).

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

643020 is a wasteful number, since it uses less digits than its factorization.

643020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1550 (or 1548 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 643020 is about 801.8852785779. The cubic root of 643020 is about 86.3127247991.

Adding to 643020 its reverse (20346), we get a palindrome (663366).

The spelling of 643020 in words is "six hundred forty-three thousand, twenty".