166540863 has 4 divisors (see below), whose sum is σ = 222054488. Its totient is φ = 111027240.

The previous prime is 166540853. The next prime is 166540879. The reversal of 166540863 is 368045661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 368045661 = 3 ⋅122681887.

It is not a de Polignac number, because 166540863 - 2⁶ = 166540799 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166540853) 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, 27756808 + ... + 27756813.

It is an arithmetic number, because the mean of its divisors is an integer number (55513622).

Almost surely, 2^166540863 is an apocalyptic number.

166540863 is a deficient number, since it is larger than the sum of its proper divisors (55513625).

166540863 is an equidigital number, since it uses as much as digits as its factorization.

166540863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55513624.

The product of its (nonzero) digits is 103680, while the sum is 39.

The square root of 166540863 is about 12905.0712125118. The cubic root of 166540863 is about 550.1827084441.

The spelling of 166540863 in words is "one hundred sixty-six million, five hundred forty thousand, eight hundred sixty-three".