66557804540660 has 72 divisors (see below), whose sum is σ = 152489762981304. Its totient is φ = 24379838023680.

The previous prime is 66557804540639. The next prime is 66557804540687. The reversal of 66557804540660 is 6604540875566.

It can be written as a sum of positive squares in 12 ways, for example, as 9962696827876 + 56595107712784 = 3156374^2 + 7522972^2 .

It is a junction number, because it is equal to n+sod(n) for n = 66557804540593 and 66557804540602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 155396831 + ... + 155824550.

Almost surely, 2^{66557804540660} is an apocalyptic number.

It is an amenable number.

66557804540660 is an abundant number, since it is smaller than the sum of its proper divisors (85931958440644).

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

66557804540660 is a wasteful number, since it uses less digits than its factorization.

66557804540660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311221461 (or 311221442 counting only the distinct ones).

The product of its (nonzero) digits is 145152000, while the sum is 62.

The spelling of 66557804540660 in words is "sixty-six trillion, five hundred fifty-seven billion, eight hundred four million, five hundred forty thousand, six hundred sixty".