66615555556 has 24 divisors (see below), whose sum is σ = 128434320000. Its totient is φ = 29979996000.

The previous prime is 66615555551. The next prime is 66615555557. The reversal of 66615555556 is 65555551666.

66615555556 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 66615555497 and 66615555506.

It is not an unprimeable number, because it can be changed into a prime (66615555551) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7490556 + ... + 7499443.

It is an arithmetic number, because the mean of its divisors is an integer number (5351430000).

Almost surely, 2^66615555556 is an apocalyptic number.

It is an amenable number.

66615555556 is a deficient number, since it is larger than the sum of its proper divisors (61818764444).

66615555556 is a wasteful number, since it uses less digits than its factorization.

66615555556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14990115 (or 14990113 counting only the distinct ones).

The product of its digits is 20250000, while the sum is 55.

The spelling of 66615555556 in words is "sixty-six billion, six hundred fifteen million, five hundred fifty-five thousand, five hundred fifty-six".