66127121 has 2 divisors, whose sum is σ = 66127122. Its totient is φ = 66127120.

The previous prime is 66127091. The next prime is 66127129. The reversal of 66127121 is 12172166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65934400 + 192721 = 8120^2 + 439^2 .

It is a cyclic number.

It is not a de Polignac number, because 66127121 - 2¹⁰ = 66126097 is a prime.

It is a super-2 number, since 2×66127121² = 8745592263497282, which contains 22 as substring.

It is equal to p_3903218 and since 66127121 and 3903218 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (66127129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33063560 + 33063561.

It is an arithmetic number, because the mean of its divisors is an integer number (33063561).

Almost surely, 2^66127121 is an apocalyptic number.

It is an amenable number.

66127121 is a deficient number, since it is larger than the sum of its proper divisors (1).

66127121 is an equidigital number, since it uses as much as digits as its factorization.

66127121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1008, while the sum is 26.

The square root of 66127121 is about 8131.8583976850. The cubic root of 66127121 is about 404.3832934762.

Adding to 66127121 its reverse (12172166), we get a palindrome (78299287).

The spelling of 66127121 in words is "sixty-six million, one hundred twenty-seven thousand, one hundred twenty-one".