643246540 has 24 divisors (see below), whose sum is σ = 1383766272. Its totient is φ = 251022720.

The previous prime is 643246529. The next prime is 643246579. The reversal of 643246540 is 45642346.

643246540 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×643246540² = 827532222443943200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 643246496 and 643246505.

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, 391404 + ... + 393043.

It is an arithmetic number, because the mean of its divisors is an integer number (57656928).

Almost surely, 2^643246540 is an apocalyptic number.

It is an amenable number.

643246540 is an abundant number, since it is smaller than the sum of its proper divisors (740519732).

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

643246540 is a wasteful number, since it uses less digits than its factorization.

643246540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 784497 (or 784495 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 34.

The square root of 643246540 is about 25362.3054945721. The cubic root of 643246540 is about 863.2285978135.

Adding to 643246540 its reverse (45642346), we get a palindrome (688888886).

The spelling of 643246540 in words is "six hundred forty-three million, two hundred forty-six thousand, five hundred forty".