66425617121 has 2 divisors, whose sum is σ = 66425617122. Its totient is φ = 66425617120.

The previous prime is 66425617117. The next prime is 66425617151. The reversal of 66425617121 is 12171652466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53298186496 + 13127430625 = 230864^2 + 114575^2 .

It is a cyclic number.

It is not a de Polignac number, because 66425617121 - 2² = 66425617117 is a prime.

It is not a weakly prime, because it can be changed into another prime (66425617151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33212808560 + 33212808561.

It is an arithmetic number, because the mean of its divisors is an integer number (33212808561).

Almost surely, 2^66425617121 is an apocalyptic number.

It is an amenable number.

66425617121 is a deficient number, since it is larger than the sum of its proper divisors (1).

66425617121 is an equidigital number, since it uses as much as digits as its factorization.

66425617121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 41.

The spelling of 66425617121 in words is "sixty-six billion, four hundred twenty-five million, six hundred seventeen thousand, one hundred twenty-one".