165666413 has 4 divisors (see below), whose sum is σ = 180727008. Its totient is φ = 150605820.

The previous prime is 165666407. The next prime is 165666421. The reversal of 165666413 is 314666561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 165666413 - 2⁶ = 165666349 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165666433) 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, 7530281 + ... + 7530302.

It is an arithmetic number, because the mean of its divisors is an integer number (45181752).

Almost surely, 2^165666413 is an apocalyptic number.

It is an amenable number.

165666413 is a deficient number, since it is larger than the sum of its proper divisors (15060595).

165666413 is a wasteful number, since it uses less digits than its factorization.

165666413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15060594.

The product of its digits is 77760, while the sum is 38.

The square root of 165666413 is about 12871.1465301270. The cubic root of 165666413 is about 549.2180767620.

The spelling of 165666413 in words is "one hundred sixty-five million, six hundred sixty-six thousand, four hundred thirteen".