643244012 has 24 divisors (see below), whose sum is σ = 1225786800. Its totient is φ = 294186816.

The previous prime is 643243999. The next prime is 643244023. The reversal of 643244012 is 210442346.

It is a super-2 number, since 2×643244012² = 827525717947712288, which contains 22 as substring.

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, 143723 + ... + 148130.

It is an arithmetic number, because the mean of its divisors is an integer number (51074450).

Almost surely, 2^643244012 is an apocalyptic number.

It is an amenable number.

643244012 is a deficient number, since it is larger than the sum of its proper divisors (582542788).

643244012 is a wasteful number, since it uses less digits than its factorization.

643244012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291905 (or 291903 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 26.

The square root of 643244012 is about 25362.2556567826. The cubic root of 643244012 is about 863.2274669641.

Adding to 643244012 its reverse (210442346), we get a palindrome (853686358).

The spelling of 643244012 in words is "six hundred forty-three million, two hundred forty-four thousand, twelve".