166321601 has 2 divisors, whose sum is σ = 166321602. Its totient is φ = 166321600.

The previous prime is 166321577. The next prime is 166321621. The reversal of 166321601 is 106123661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 160680976 + 5640625 = 12676^2 + 2375^2 .

It is a cyclic number.

It is not a de Polignac number, because 166321601 - 2¹⁰ = 166320577 is a prime.

It is not a weakly prime, because it can be changed into another prime (166321621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83160800 + 83160801.

It is an arithmetic number, because the mean of its divisors is an integer number (83160801).

Almost surely, 2^166321601 is an apocalyptic number.

It is an amenable number.

166321601 is a deficient number, since it is larger than the sum of its proper divisors (1).

166321601 is an equidigital number, since it uses as much as digits as its factorization.

166321601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 166321601 is about 12896.5732270243. The cubic root of 166321601 is about 549.9411518304.

The spelling of 166321601 in words is "one hundred sixty-six million, three hundred twenty-one thousand, six hundred one".