643799650 has 48 divisors (see below), whose sum is σ = 1308916224. Its totient is φ = 234146880.

The previous prime is 643799641. The next prime is 643799657. The reversal of 643799650 is 56997346.

It is a junction number, because it is equal to n+sod(n) for n = 643799594 and 643799603.

It is not an unprimeable number, because it can be changed into a prime (643799657) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 36159 + ... + 50941.

It is an arithmetic number, because the mean of its divisors is an integer number (27269088).

Almost surely, 2^643799650 is an apocalyptic number.

643799650 is an abundant number, since it is smaller than the sum of its proper divisors (665116574).

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

643799650 is a wasteful number, since it uses less digits than its factorization.

643799650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14875 (or 14870 counting only the distinct ones).

The product of its (nonzero) digits is 1224720, while the sum is 49.

The square root of 643799650 is about 25373.2073258388. The cubic root of 643799650 is about 863.4759491029.

The spelling of 643799650 in words is "six hundred forty-three million, seven hundred ninety-nine thousand, six hundred fifty".