66590555509566 has 96 divisors (see below), whose sum is σ = 165053759101920. Its totient is φ = 19216237824000.

The previous prime is 66590555509561. The next prime is 66590555509627.

66590555509566 is a `hidden beast` number, since 6 + 6 + 5 + 9 + 0 + 5 + 5 + 5 + 50 + 9 + 566 = 666.

66590555509566 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 66590555509494 and 66590555509503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66590555509561) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 79013035 + ... + 79851366.

It is an arithmetic number, because the mean of its divisors is an integer number (1719309990645).

Almost surely, 2^{66590555509566} is an apocalyptic number.

66590555509566 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

66590555509566 is an abundant number, since it is smaller than the sum of its proper divisors (98463203592354).

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

66590555509566 is a wasteful number, since it uses less digits than its factorization.

66590555509566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158864522 (or 158864519 counting only the distinct ones).

The product of its (nonzero) digits is 1640250000, while the sum is 72.

The spelling of 66590555509566 in words is "sixty-six trillion, five hundred ninety billion, five hundred fifty-five million, five hundred nine thousand, five hundred sixty-six".