66561364600 has 48 divisors (see below), whose sum is σ = 158937762600. Its totient is φ = 25904960640.

The previous prime is 66561364577. The next prime is 66561364619. The reversal of 66561364600 is 646316566.

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, 4489990 + ... + 4504789.

Almost surely, 2^66561364600 is an apocalyptic number.

It is an amenable number.

66561364600 is an abundant number, since it is smaller than the sum of its proper divisors (92376398000).

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

66561364600 is a wasteful number, since it uses less digits than its factorization.

66561364600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8994832 (or 8994823 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 43.

The spelling of 66561364600 in words is "sixty-six billion, five hundred sixty-one million, three hundred sixty-four thousand, six hundred".