166565515 has 4 divisors (see below), whose sum is σ = 199878624. Its totient is φ = 133252408.

The previous prime is 166565513. The next prime is 166565569. The reversal of 166565515 is 515565661.

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 166565515 - 2¹ = 166565513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166565513) 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, 16656547 + ... + 16656556.

It is an arithmetic number, because the mean of its divisors is an integer number (49969656).

Almost surely, 2^166565515 is an apocalyptic number.

166565515 is a deficient number, since it is larger than the sum of its proper divisors (33313109).

166565515 is an equidigital number, since it uses as much as digits as its factorization.

166565515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33313108.

The product of its digits is 135000, while the sum is 40.

The square root of 166565515 is about 12906.0263055675. The cubic root of 166565515 is about 550.2098538039.

The spelling of 166565515 in words is "one hundred sixty-six million, five hundred sixty-five thousand, five hundred fifteen".