643620250 has 128 divisors (see below), whose sum is σ = 1561996800. Its totient is φ = 192844800.

The previous prime is 643620239. The next prime is 643620283. The reversal of 643620250 is 52026346.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 431506 + ... + 432994.

It is an arithmetic number, because the mean of its divisors is an integer number (12203100).

Almost surely, 2^643620250 is an apocalyptic number.

643620250 is an abundant number, since it is smaller than the sum of its proper divisors (918376550).

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

643620250 is a wasteful number, since it uses less digits than its factorization.

643620250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1545 (or 1535 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 643620250 is about 25369.6718544013. The cubic root of 643620250 is about 863.3957367904.

Adding to 643620250 its reverse (52026346), we get a palindrome (695646596).

The spelling of 643620250 in words is "six hundred forty-three million, six hundred twenty thousand, two hundred fifty".