165378618 has 64 divisors (see below), whose sum is σ = 397509120. Its totient is φ = 50766336.

The previous prime is 165378613. The next prime is 165378623. The reversal of 165378618 is 816873561.

It is an interprime number because it is at equal distance from previous prime (165378613) and next prime (165378623).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (165378611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 41230 + ... + 45062.

It is an arithmetic number, because the mean of its divisors is an integer number (6211080).

Almost surely, 2^165378618 is an apocalyptic number.

165378618 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 165378618, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (198754560).

165378618 is an abundant number, since it is smaller than the sum of its proper divisors (232130502).

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

165378618 is a wasteful number, since it uses less digits than its factorization.

165378618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3908 (or 3902 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The square root of 165378618 is about 12859.9618195390. The cubic root of 165378618 is about 548.8998593066.

The spelling of 165378618 in words is "one hundred sixty-five million, three hundred seventy-eight thousand, six hundred eighteen".