643986460900 has 36 divisors (see below), whose sum is σ = 1397511304420. Its totient is φ = 257583398400.

The previous prime is 643986460879. The next prime is 643986460903. The reversal of 643986460900 is 9064689346.

It can be written as a sum of positive squares in 6 ways, for example, as 74178880164 + 569807580736 = 272358^2 + 754856^2 .

It is not an unprimeable number, because it can be changed into a prime (643986460903) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2404936 + ... + 2659264.

Almost surely, 2^643986460900 is an apocalyptic number.

It is an amenable number.

643986460900 is an abundant number, since it is smaller than the sum of its proper divisors (753524843520).

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

643986460900 is a wasteful number, since it uses less digits than its factorization.

643986460900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 279664 (or 279657 counting only the distinct ones).

The product of its (nonzero) digits is 6718464, while the sum is 55.

The spelling of 643986460900 in words is "six hundred forty-three billion, nine hundred eighty-six million, four hundred sixty thousand, nine hundred".