66961833121 has 2 divisors, whose sum is σ = 66961833122. Its totient is φ = 66961833120.

The previous prime is 66961833067. The next prime is 66961833131. The reversal of 66961833121 is 12133816966.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41387426721 + 25574406400 = 203439^2 + 159920^2 .

It is a cyclic number.

It is not a de Polignac number, because 66961833121 - 2³⁵ = 32602094753 is a prime.

It is not a weakly prime, because it can be changed into another prime (66961833131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33480916560 + 33480916561.

It is an arithmetic number, because the mean of its divisors is an integer number (33480916561).

Almost surely, 2^66961833121 is an apocalyptic number.

It is an amenable number.

66961833121 is a deficient number, since it is larger than the sum of its proper divisors (1).

66961833121 is an equidigital number, since it uses as much as digits as its factorization.

66961833121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 279936, while the sum is 46.

The spelling of 66961833121 in words is "sixty-six billion, nine hundred sixty-one million, eight hundred thirty-three thousand, one hundred twenty-one".