216165389 has 4 divisors (see below), whose sum is σ = 235816800. Its totient is φ = 196513980.

The previous prime is 216165347. The next prime is 216165401. The reversal of 216165389 is 983561612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216165389 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216165289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9825689 + ... + 9825710.

It is an arithmetic number, because the mean of its divisors is an integer number (58954200).

Almost surely, 2^216165389 is an apocalyptic number.

It is an amenable number.

216165389 is a deficient number, since it is larger than the sum of its proper divisors (19651411).

216165389 is a wasteful number, since it uses less digits than its factorization.

216165389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19651410.

The product of its digits is 77760, while the sum is 41.

The square root of 216165389 is about 14702.5640280871. The cubic root of 216165389 is about 600.1530988942.

The spelling of 216165389 in words is "two hundred sixteen million, one hundred sixty-five thousand, three hundred eighty-nine".