643248656450 has 24 divisors (see below), whose sum is σ = 1196865088068. Its totient is φ = 257208583680.

The previous prime is 643248656423. The next prime is 643248656527. The reversal of 643248656450 is 54656842346.

It can be written as a sum of positive squares in 6 ways, for example, as 216488270089 + 426760386361 = 465283^2 + 653269^2 .

It is a super-3 number, since 3×643248656450³ (a number of 36 digits) contains 333 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 643248656392 and 643248656401.

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, 2128907 + ... + 2412206.

Almost surely, 2^643248656450 is an apocalyptic number.

643248656450 is a deficient number, since it is larger than the sum of its proper divisors (553616431618).

643248656450 is a wasteful number, since it uses less digits than its factorization.

643248656450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4543958 (or 4543953 counting only the distinct ones).

The product of its (nonzero) digits is 16588800, while the sum is 53.

The spelling of 643248656450 in words is "six hundred forty-three billion, two hundred forty-eight million, six hundred fifty-six thousand, four hundred fifty".