166681607 has 2 divisors, whose sum is σ = 166681608. Its totient is φ = 166681606.

The previous prime is 166681597. The next prime is 166681609. The reversal of 166681607 is 706186661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 166681607 - 2⁸ = 166681351 is a prime.

It is a super-2 number, since 2×166681607² = 55565516224204898, which contains 22 as substring.

Together with 166681609, it forms a pair of twin primes.

It is a Chen prime.

It is a nialpdrome in base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166681609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83340803 + 83340804.

It is an arithmetic number, because the mean of its divisors is an integer number (83340804).

Almost surely, 2^166681607 is an apocalyptic number.

166681607 is a deficient number, since it is larger than the sum of its proper divisors (1).

166681607 is an equidigital number, since it uses as much as digits as its factorization.

166681607 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 166681607 is about 12910.5231110130. The cubic root of 166681607 is about 550.3376516224.

The spelling of 166681607 in words is "one hundred sixty-six million, six hundred eighty-one thousand, six hundred seven".