166516606406503 has 2 divisors, whose sum is σ = 166516606406504. Its totient is φ = 166516606406502.

The previous prime is 166516606406471. The next prime is 166516606406519. The reversal of 166516606406503 is 305604606615661.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 166516606406503 - 2⁵ = 166516606406471 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166516606406303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83258303203251 + 83258303203252.

It is an arithmetic number, because the mean of its divisors is an integer number (83258303203252).

Almost surely, 2^{166516606406503} is an apocalyptic number.

166516606406503 is a deficient number, since it is larger than the sum of its proper divisors (1).

166516606406503 is an equidigital number, since it uses as much as digits as its factorization.

166516606406503 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13996800, while the sum is 55.

The spelling of 166516606406503 in words is "one hundred sixty-six trillion, five hundred sixteen billion, six hundred six million, four hundred six thousand, five hundred three".