165638479 has 4 divisors (see below), whose sum is σ = 172840176. Its totient is φ = 158436784.

The previous prime is 165638443. The next prime is 165638491. The reversal of 165638479 is 974836561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 974836561 = 251 ⋅3883811.

It is a cyclic number.

It is not a de Polignac number, because 165638479 - 2¹⁵ = 165605711 is a prime.

It is a super-2 number, since 2×165638479² = 54872211450866882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165638579) 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, 3600814 + ... + 3600859.

It is an arithmetic number, because the mean of its divisors is an integer number (43210044).

Almost surely, 2^165638479 is an apocalyptic number.

165638479 is a deficient number, since it is larger than the sum of its proper divisors (7201697).

165638479 is an equidigital number, since it uses as much as digits as its factorization.

165638479 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7201696.

The product of its digits is 1088640, while the sum is 49.

The square root of 165638479 is about 12870.0613440651. The cubic root of 165638479 is about 549.1872060505.

The spelling of 165638479 in words is "one hundred sixty-five million, six hundred thirty-eight thousand, four hundred seventy-nine".