643665412660 has 96 divisors (see below), whose sum is σ = 1401936947712. Its totient is φ = 248079928320.

The previous prime is 643665412657. The next prime is 643665412673. The reversal of 643665412660 is 66214566346.

643665412660 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 38624730 + ... + 38641390.

It is an arithmetic number, because the mean of its divisors is an integer number (14603509872).

Almost surely, 2^643665412660 is an apocalyptic number.

It is an amenable number.

643665412660 is an abundant number, since it is smaller than the sum of its proper divisors (758271535052).

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

643665412660 is a wasteful number, since it uses less digits than its factorization.

643665412660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17353 (or 17351 counting only the distinct ones).

The product of its (nonzero) digits is 3732480, while the sum is 49.

The spelling of 643665412660 in words is "six hundred forty-three billion, six hundred sixty-five million, four hundred twelve thousand, six hundred sixty".