66666655334441 has 2 divisors, whose sum is σ = 66666655334442. Its totient is φ = 66666655334440.

The previous prime is 66666655334393. The next prime is 66666655334449. The reversal of 66666655334441 is 14443355666666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65317350067225 + 1349305267216 = 8081915^2 + 1161596^2 .

It is a cyclic number.

It is not a de Polignac number, because 66666655334441 - 2¹⁴ = 66666655318057 is a prime.

It is not a weakly prime, because it can be changed into another prime (66666655334449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33333327667220 + 33333327667221.

It is an arithmetic number, because the mean of its divisors is an integer number (33333327667221).

Almost surely, 2^{66666655334441} is an apocalyptic number.

It is an amenable number.

66666655334441 is a deficient number, since it is larger than the sum of its proper divisors (1).

66666655334441 is an equidigital number, since it uses as much as digits as its factorization.

66666655334441 is an evil number, because the sum of its binary digits is even.

The product of its digits is 671846400, while the sum is 65.

The spelling of 66666655334441 in words is "sixty-six trillion, six hundred sixty-six billion, six hundred fifty-five million, three hundred thirty-four thousand, four hundred forty-one".