66105555550 has 24 divisors (see below), whose sum is σ = 123692614416. Its totient is φ = 26283882240.

The previous prime is 66105555499. The next prime is 66105555553. The reversal of 66105555550 is 5555550166.

It is a junction number, because it is equal to n+sod(n) for n = 66105555497 and 66105555506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66105555553) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3950067 + ... + 3966766.

It is an arithmetic number, because the mean of its divisors is an integer number (5153858934).

Almost surely, 2^66105555550 is an apocalyptic number.

66105555550 is a deficient number, since it is larger than the sum of its proper divisors (57587058866).

66105555550 is a wasteful number, since it uses less digits than its factorization.

66105555550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7917012 (or 7917007 counting only the distinct ones).

The product of its (nonzero) digits is 562500, while the sum is 43.

The spelling of 66105555550 in words is "sixty-six billion, one hundred five million, five hundred fifty-five thousand, five hundred fifty".