66656561055 has 32 divisors (see below), whose sum is σ = 122396313600. Its totient is φ = 30344063232.

The previous prime is 66656561053. The next prime is 66656561113. The reversal of 66656561055 is 55016565666.

It is not a de Polignac number, because 66656561055 - 2¹ = 66656561053 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66656560989 and 66656561007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66656561053) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1302990 + ... + 1353179.

It is an arithmetic number, because the mean of its divisors is an integer number (3824884800).

Almost surely, 2^66656561055 is an apocalyptic number.

66656561055 is a deficient number, since it is larger than the sum of its proper divisors (55739752545).

66656561055 is a wasteful number, since it uses less digits than its factorization.

66656561055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2656423.

The product of its (nonzero) digits is 4860000, while the sum is 51.

The spelling of 66656561055 in words is "sixty-six billion, six hundred fifty-six million, five hundred sixty-one thousand, fifty-five".