66551555673 has 12 divisors (see below), whose sum is σ = 96148241748. Its totient is φ = 44359296000.

The previous prime is 66551555659. The next prime is 66551555689. The reversal of 66551555673 is 37655515566.

66551555673 is a `hidden beast` number, since 6 + 6 + 5 + 5 + 15 + 556 + 73 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 59693728329 + 6857827344 = 244323^2 + 82812^2 .

It is not a de Polignac number, because 66551555673 - 2¹³ = 66551547481 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66551551673) 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, 650328 + ... + 745673.

It is an arithmetic number, because the mean of its divisors is an integer number (8012353479).

Almost surely, 2^66551555673 is an apocalyptic number.

It is an amenable number.

66551555673 is a deficient number, since it is larger than the sum of its proper divisors (29596686075).

66551555673 is a wasteful number, since it uses less digits than its factorization.

66551555673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1401304 (or 1401301 counting only the distinct ones).

The product of its digits is 14175000, while the sum is 54.

The spelling of 66551555673 in words is "sixty-six billion, five hundred fifty-one million, five hundred fifty-five thousand, six hundred seventy-three".