165520711 has 4 divisors (see below), whose sum is σ = 167788192. Its totient is φ = 163253232.

The previous prime is 165520709. The next prime is 165520759. The reversal of 165520711 is 117025561.

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 165520711 - 2¹ = 165520709 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 165520711.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165520111) 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, 1133631 + ... + 1133776.

It is an arithmetic number, because the mean of its divisors is an integer number (41947048).

Almost surely, 2^165520711 is an apocalyptic number.

165520711 is a deficient number, since it is larger than the sum of its proper divisors (2267481).

165520711 is an equidigital number, since it uses as much as digits as its factorization.

165520711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2267480.

The product of its (nonzero) digits is 2100, while the sum is 28.

The square root of 165520711 is about 12865.4852609608. The cubic root of 165520711 is about 549.0570188831.

It can be divided in two parts, 1655 and 20711, that added together give a triangular number (22366 = T₂₁₁).

The spelling of 165520711 in words is "one hundred sixty-five million, five hundred twenty thousand, seven hundred eleven".