166561327 has 2 divisors, whose sum is σ = 166561328. Its totient is φ = 166561326.

The previous prime is 166561321. The next prime is 166561411. The reversal of 166561327 is 723165661.

It is a weak prime.

It is an emirp because it is prime and its reverse (723165661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166561327 - 2¹¹ = 166559279 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166561321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83280663 + 83280664.

It is an arithmetic number, because the mean of its divisors is an integer number (83280664).

Almost surely, 2^166561327 is an apocalyptic number.

166561327 is a deficient number, since it is larger than the sum of its proper divisors (1).

166561327 is an equidigital number, since it uses as much as digits as its factorization.

166561327 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45360, while the sum is 37.

The square root of 166561327 is about 12905.8640547621. The cubic root of 166561327 is about 550.2052424088.

The spelling of 166561327 in words is "one hundred sixty-six million, five hundred sixty-one thousand, three hundred twenty-seven".