166689427 has 4 divisors (see below), whose sum is σ = 166857616. Its totient is φ = 166521240.

The previous prime is 166689421. The next prime is 166689463. The reversal of 166689427 is 724986661.

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

It is a cyclic number.

It is not a de Polignac number, because 166689427 - 2¹¹ = 166687379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166689421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82599 + ... + 84592.

It is an arithmetic number, because the mean of its divisors is an integer number (41714404).

Almost surely, 2^166689427 is an apocalyptic number.

166689427 is a deficient number, since it is larger than the sum of its proper divisors (168189).

166689427 is an equidigital number, since it uses as much as digits as its factorization.

166689427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168188.

The product of its digits is 870912, while the sum is 49.

The square root of 166689427 is about 12910.8259611847. The cubic root of 166689427 is about 550.3462579971.

The spelling of 166689427 in words is "one hundred sixty-six million, six hundred eighty-nine thousand, four hundred twenty-seven".