643475550 has 24 divisors (see below), whose sum is σ = 1595819736. Its totient is φ = 171593440.

The previous prime is 643475533. The next prime is 643475563. The reversal of 643475550 is 55574346.

643475550 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 643475499 and 643475508.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2144769 + ... + 2145068.

It is an arithmetic number, because the mean of its divisors is an integer number (66492489).

Almost surely, 2^643475550 is an apocalyptic number.

643475550 is an abundant number, since it is smaller than the sum of its proper divisors (952344186).

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

643475550 is a wasteful number, since it uses less digits than its factorization.

643475550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4289852 (or 4289847 counting only the distinct ones).

The product of its (nonzero) digits is 252000, while the sum is 39.

The square root of 643475550 is about 25366.8198637512. The cubic root of 643475550 is about 863.3310284851.

The spelling of 643475550 in words is "six hundred forty-three million, four hundred seventy-five thousand, five hundred fifty".