66664321172 has 6 divisors (see below), whose sum is σ = 116662562058. Its totient is φ = 33332160584.

The previous prime is 66664321159. The next prime is 66664321247. The reversal of 66664321172 is 27112346666.

It can be written as a sum of positive squares in only one way, i.e., 64767196036 + 1897125136 = 254494^2 + 43556^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8333040143 + ... + 8333040150.

It is an arithmetic number, because the mean of its divisors is an integer number (19443760343).

Almost surely, 2^66664321172 is an apocalyptic number.

It is an amenable number.

66664321172 is a deficient number, since it is larger than the sum of its proper divisors (49998240886).

66664321172 is a wasteful number, since it uses less digits than its factorization.

66664321172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16666080297 (or 16666080295 counting only the distinct ones).

The product of its digits is 435456, while the sum is 44.

The spelling of 66664321172 in words is "sixty-six billion, six hundred sixty-four million, three hundred twenty-one thousand, one hundred seventy-two".