166719997 has 2 divisors, whose sum is σ = 166719998. Its totient is φ = 166719996.

The previous prime is 166719991. The next prime is 166720007. The reversal of 166719997 is 799917661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 104325796 + 62394201 = 10214^2 + 7899^2 .

It is a cyclic number.

It is not a de Polignac number, because 166719997 - 2¹¹ = 166717949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166719991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83359998 + 83359999.

It is an arithmetic number, because the mean of its divisors is an integer number (83359999).

Almost surely, 2^166719997 is an apocalyptic number.

It is an amenable number.

166719997 is a deficient number, since it is larger than the sum of its proper divisors (1).

166719997 is an equidigital number, since it uses as much as digits as its factorization.

166719997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1285956, while the sum is 55.

The square root of 166719997 is about 12912.0097970843. The cubic root of 166719997 is about 550.3798995164.

The spelling of 166719997 in words is "one hundred sixty-six million, seven hundred nineteen thousand, nine hundred ninety-seven".