42166009 has 2 divisors, whose sum is σ = 42166010. Its totient is φ = 42166008.

The previous prime is 42165989. The next prime is 42166031. The reversal of 42166009 is 90066124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32262400 + 9903609 = 5680^2 + 3147^2 .

It is a cyclic number.

It is not a de Polignac number, because 42166009 - 2⁷ = 42165881 is a prime.

It is not a weakly prime, because it can be changed into another prime (42166049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21083004 + 21083005.

It is an arithmetic number, because the mean of its divisors is an integer number (21083005).

Almost surely, 2^42166009 is an apocalyptic number.

It is an amenable number.

42166009 is a deficient number, since it is larger than the sum of its proper divisors (1).

42166009 is an equidigital number, since it uses as much as digits as its factorization.

42166009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 42166009 is about 6493.5359396865. The cubic root of 42166009 is about 348.0600399557.

It can be divided in two parts, 421 and 66009, that added together give a triangular number (66430 = T₃₆₄).

The spelling of 42166009 in words is "forty-two million, one hundred sixty-six thousand, nine".