166000621 has 2 divisors, whose sum is σ = 166000622. Its totient is φ = 166000620.

The previous prime is 166000619. The next prime is 166000633. The reversal of 166000621 is 126000661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 149108521 + 16892100 = 12211^2 + 4110^2 .

It is an emirp because it is prime and its reverse (126000661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166000621 - 2¹ = 166000619 is a prime.

Together with 166000619, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 166000592 and 166000601.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166000661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83000310 + 83000311.

It is an arithmetic number, because the mean of its divisors is an integer number (83000311).

Almost surely, 2^166000621 is an apocalyptic number.

It is an amenable number.

166000621 is a deficient number, since it is larger than the sum of its proper divisors (1).

166000621 is an equidigital number, since it uses as much as digits as its factorization.

166000621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 166000621 is about 12884.1228261764. The cubic root of 166000621 is about 549.5871513363.

The spelling of 166000621 in words is "one hundred sixty-six million, six hundred twenty-one", and thus it is an aban number.