166561267 has 4 divisors (see below), whose sum is σ = 166656160. Its totient is φ = 166466376.

The previous prime is 166561261. The next prime is 166561273. The reversal of 166561267 is 762165661.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (166561261) and next prime (166561273).

It is a cyclic number.

It is not a de Polignac number, because 166561267 - 2³ = 166561259 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166561261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44763 + ... + 48340.

It is an arithmetic number, because the mean of its divisors is an integer number (41664040).

Almost surely, 2^166561267 is an apocalyptic number.

166561267 is a deficient number, since it is larger than the sum of its proper divisors (94893).

166561267 is an equidigital number, since it uses as much as digits as its factorization.

166561267 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94892.

The product of its digits is 90720, while the sum is 40.

The square root of 166561267 is about 12905.8617302372. The cubic root of 166561267 is about 550.2051763424.

The spelling of 166561267 in words is "one hundred sixty-six million, five hundred sixty-one thousand, two hundred sixty-seven".