166540015 has 4 divisors (see below), whose sum is σ = 199848024. Its totient is φ = 133232008.

The previous prime is 166540013. The next prime is 166540019. The reversal of 166540015 is 510045661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 510045661 = 43 ⋅11861527.

It is a cyclic number.

It is not a de Polignac number, because 166540015 - 2¹ = 166540013 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 (166540013) 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, 16653997 + ... + 16654006.

It is an arithmetic number, because the mean of its divisors is an integer number (49962006).

Almost surely, 2^166540015 is an apocalyptic number.

166540015 is a deficient number, since it is larger than the sum of its proper divisors (33308009).

166540015 is an equidigital number, since it uses as much as digits as its factorization.

166540015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33308008.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 166540015 is about 12905.0383571689. The cubic root of 166540015 is about 550.1817746277.

Adding to 166540015 its reverse (510045661), we get a palindrome (676585676).

The spelling of 166540015 in words is "one hundred sixty-six million, five hundred forty thousand, fifteen".