165515550 has 24 divisors (see below), whose sum is σ = 410478936. Its totient is φ = 44137440.

The previous prime is 165515531. The next prime is 165515561. The reversal of 165515550 is 55515561.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 551569 + ... + 551868.

It is an arithmetic number, because the mean of its divisors is an integer number (17103289).

Almost surely, 2^165515550 is an apocalyptic number.

165515550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

165515550 is an abundant number, since it is smaller than the sum of its proper divisors (244963386).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

165515550 is a wasteful number, since it uses less digits than its factorization.

165515550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1103452 (or 1103447 counting only the distinct ones).

The product of its (nonzero) digits is 18750, while the sum is 33.

The square root of 165515550 is about 12865.2846839858. The cubic root of 165515550 is about 549.0513122202.

It can be divided in two parts, 1655 and 15550, that added together give a triangular number (17205 = T₁₈₅).

The spelling of 165515550 in words is "one hundred sixty-five million, five hundred fifteen thousand, five hundred fifty".