166281001 has 2 divisors, whose sum is σ = 166281002. Its totient is φ = 166281000.

The previous prime is 166280999. The next prime is 166281013. The reversal of 166281001 is 100182661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 135489600 + 30791401 = 11640^2 + 5549^2 .

It is a cyclic number.

It is not a de Polignac number, because 166281001 - 2¹ = 166280999 is a prime.

Together with 166280999, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (166281091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83140500 + 83140501.

It is an arithmetic number, because the mean of its divisors is an integer number (83140501).

Almost surely, 2^166281001 is an apocalyptic number.

It is an amenable number.

166281001 is a deficient number, since it is larger than the sum of its proper divisors (1).

166281001 is an equidigital number, since it uses as much as digits as its factorization.

166281001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 166281001 is about 12894.9990694067. Note that the first 3 decimals coincide. The cubic root of 166281001 is about 549.8964003216.

The spelling of 166281001 in words is "one hundred sixty-six million, two hundred eighty-one thousand, one".