66121201 has 2 divisors, whose sum is σ = 66121202. Its totient is φ = 66121200.

The previous prime is 66121199. The next prime is 66121243. The reversal of 66121201 is 10212166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61214976 + 4906225 = 7824^2 + 2215^2 .

It is a cyclic number.

It is not a de Polignac number, because 66121201 - 2¹ = 66121199 is a prime.

Together with 66121199, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (66121261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33060600 + 33060601.

It is an arithmetic number, because the mean of its divisors is an integer number (33060601).

Almost surely, 2^66121201 is an apocalyptic number.

It is an amenable number.

66121201 is a deficient number, since it is larger than the sum of its proper divisors (1).

66121201 is an equidigital number, since it uses as much as digits as its factorization.

66121201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 66121201 is about 8131.4943891022. The cubic root of 66121201 is about 404.3712257069.

Adding to 66121201 its reverse (10212166), we get a palindrome (76333367).

The spelling of 66121201 in words is "sixty-six million, one hundred twenty-one thousand, two hundred one".