166000921 has 2 divisors, whose sum is σ = 166000922. Its totient is φ = 166000920.

The previous prime is 166000819. The next prime is 166000949. The reversal of 166000921 is 129000661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 149719696 + 16281225 = 12236^2 + 4035^2 .

It is a cyclic number.

It is not a de Polignac number, because 166000921 - 2²¹ = 163903769 is a prime.

It is not a weakly prime, because it can be changed into another prime (166000951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83000460 + 83000461.

It is an arithmetic number, because the mean of its divisors is an integer number (83000461).

Almost surely, 2^166000921 is an apocalyptic number.

It is an amenable number.

166000921 is a deficient number, since it is larger than the sum of its proper divisors (1).

166000921 is an equidigital number, since it uses as much as digits as its factorization.

166000921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 166000921 is about 12884.1344684073. The cubic root of 166000921 is about 549.5874824115.

The spelling of 166000921 in words is "one hundred sixty-six million, nine hundred twenty-one", and thus it is an aban number.