66640661550226 has 16 divisors (see below), whose sum is σ = 100694491973496. Its totient is φ = 33075849527296.

The previous prime is 66640661550217. The next prime is 66640661550251. The reversal of 66640661550226 is 62205516604666.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 66552066623025 + 88594927201 = 8157945^2 + 297649^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2526930 + ... + 11818066.

Almost surely, 2^{66640661550226} is an apocalyptic number.

66640661550226 is a deficient number, since it is larger than the sum of its proper divisors (34053830423270).

66640661550226 is a wasteful number, since it uses less digits than its factorization.

66640661550226 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9317453.

The product of its (nonzero) digits is 18662400, while the sum is 55.

The spelling of 66640661550226 in words is "sixty-six trillion, six hundred forty billion, six hundred sixty-one million, five hundred fifty thousand, two hundred twenty-six".