643612 has 6 divisors (see below), whose sum is σ = 1126328. Its totient is φ = 321804.

The previous prime is 643589. The next prime is 643619. The reversal of 643612 is 216346.

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 (643619) by changing a digit.

643612 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80448 + ... + 80455.

2⁶⁴³⁶¹² is an apocalyptic number.

It is an amenable number.

643612 is a deficient number, since it is larger than the sum of its proper divisors (482716).

643612 is a wasteful number, since it uses less digits than its factorization.

643612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160907 (or 160905 counting only the distinct ones).

The product of its digits is 864, while the sum is 22.

The square root of 643612 is about 802.2543237652. The cubic root of 643612 is about 86.3392047739.

Adding to 643612 its reverse (216346), we get a palindrome (859958).

The spelling of 643612 in words is "six hundred forty-three thousand, six hundred twelve".