66567106421 has 2 divisors, whose sum is σ = 66567106422. Its totient is φ = 66567106420.

The previous prime is 66567106399. The next prime is 66567106439. The reversal of 66567106421 is 12460176566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46321800625 + 20245305796 = 215225^2 + 142286^2 .

It is a cyclic number.

It is not a de Polignac number, because 66567106421 - 2⁶ = 66567106357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66567106451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33283553210 + 33283553211.

It is an arithmetic number, because the mean of its divisors is an integer number (33283553211).

Almost surely, 2^66567106421 is an apocalyptic number.

It is an amenable number.

66567106421 is a deficient number, since it is larger than the sum of its proper divisors (1).

66567106421 is an equidigital number, since it uses as much as digits as its factorization.

66567106421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 362880, while the sum is 44.

The spelling of 66567106421 in words is "sixty-six billion, five hundred sixty-seven million, one hundred six thousand, four hundred twenty-one".