166620116281 has 2 divisors, whose sum is σ = 166620116282. Its totient is φ = 166620116280.

The previous prime is 166620116261. The next prime is 166620116317. The reversal of 166620116281 is 182611026661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 150091157056 + 16528959225 = 387416^2 + 128565^2 .

It is a cyclic number.

It is not a de Polignac number, because 166620116281 - 2¹³ = 166620108089 is a prime.

It is a super-2 number, since 2×166620116281² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (166620116251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83310058140 + 83310058141.

It is an arithmetic number, because the mean of its divisors is an integer number (83310058141).

Almost surely, 2^166620116281 is an apocalyptic number.

It is an amenable number.

166620116281 is a deficient number, since it is larger than the sum of its proper divisors (1).

166620116281 is an equidigital number, since it uses as much as digits as its factorization.

166620116281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 40.

The spelling of 166620116281 in words is "one hundred sixty-six billion, six hundred twenty million, one hundred sixteen thousand, two hundred eighty-one".