166798609 has 2 divisors, whose sum is σ = 166798610. Its totient is φ = 166798608.

The previous prime is 166798601. The next prime is 166798613. The reversal of 166798609 is 906897661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 119574225 + 47224384 = 10935^2 + 6872^2 .

It is a cyclic number.

It is not a de Polignac number, because 166798609 - 2³ = 166798601 is a prime.

It is not a weakly prime, because it can be changed into another prime (166798601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83399304 + 83399305.

It is an arithmetic number, because the mean of its divisors is an integer number (83399305).

Almost surely, 2^166798609 is an apocalyptic number.

It is an amenable number.

166798609 is a deficient number, since it is larger than the sum of its proper divisors (1).

166798609 is an equidigital number, since it uses as much as digits as its factorization.

166798609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 979776, while the sum is 52.

The square root of 166798609 is about 12915.0535809961. The cubic root of 166798609 is about 550.4663911728.

The spelling of 166798609 in words is "one hundred sixty-six million, seven hundred ninety-eight thousand, six hundred nine".