166417929221 has 2 divisors, whose sum is σ = 166417929222. Its totient is φ = 166417929220.

The previous prime is 166417929211. The next prime is 166417929241. The reversal of 166417929221 is 122929714661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 164317540321 + 2100388900 = 405361^2 + 45830^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166417929221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 166417929221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166417929211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83208964610 + 83208964611.

It is an arithmetic number, because the mean of its divisors is an integer number (83208964611).

Almost surely, 2^166417929221 is an apocalyptic number.

It is an amenable number.

166417929221 is a deficient number, since it is larger than the sum of its proper divisors (1).

166417929221 is an equidigital number, since it uses as much as digits as its factorization.

166417929221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 653184, while the sum is 50.

The spelling of 166417929221 in words is "one hundred sixty-six billion, four hundred seventeen million, nine hundred twenty-nine thousand, two hundred twenty-one".