165388876385 has 4 divisors (see below), whose sum is σ = 198466651668. Its totient is φ = 132311101104.

The previous prime is 165388876379. The next prime is 165388876397. The reversal of 165388876385 is 583678883561.

It is a happy number.

165388876385 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 583678883561 = 10427 ⋅55977643.

It can be written as a sum of positive squares in 2 ways, for example, as 34646610496 + 130742265889 = 186136^2 + 361583^2 .

It is a cyclic number.

It is not a de Polignac number, because 165388876385 - 2²⁸ = 165120440929 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16538887634 + ... + 16538887643.

It is an arithmetic number, because the mean of its divisors is an integer number (49616662917).

Almost surely, 2^165388876385 is an apocalyptic number.

It is an amenable number.

165388876385 is a deficient number, since it is larger than the sum of its proper divisors (33077775283).

165388876385 is an equidigital number, since it uses as much as digits as its factorization.

165388876385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33077775282.

The product of its digits is 232243200, while the sum is 68.

The spelling of 165388876385 in words is "one hundred sixty-five billion, three hundred eighty-eight million, eight hundred seventy-six thousand, three hundred eighty-five".