66475555801 has 2 divisors, whose sum is σ = 66475555802. Its totient is φ = 66475555800.

The previous prime is 66475555763. The next prime is 66475555823. The reversal of 66475555801 is 10855557466.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55545062400 + 10930493401 = 235680^2 + 104549^2 .

It is a cyclic number.

It is not a de Polignac number, because 66475555801 - 2¹⁵ = 66475523033 is a prime.

It is not a weakly prime, because it can be changed into another prime (66475555301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33237777900 + 33237777901.

It is an arithmetic number, because the mean of its divisors is an integer number (33237777901).

Almost surely, 2^66475555801 is an apocalyptic number.

It is an amenable number.

66475555801 is a deficient number, since it is larger than the sum of its proper divisors (1).

66475555801 is an equidigital number, since it uses as much as digits as its factorization.

66475555801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5040000, while the sum is 52.

The spelling of 66475555801 in words is "sixty-six billion, four hundred seventy-five million, five hundred fifty-five thousand, eight hundred one".