165215406 has 8 divisors (see below), whose sum is σ = 330430824. Its totient is φ = 55071800.

The previous prime is 165215377. The next prime is 165215419. The reversal of 165215406 is 604512561.

It is a sphenic number, since it is the product of 3 distinct primes.

165215406 is an admirable number.

It is a super-2 number, since 2×165215406² = 54592260759489672, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 13767945 + ... + 13767956.

It is an arithmetic number, because the mean of its divisors is an integer number (41303853).

Almost surely, 2^165215406 is an apocalyptic number.

165215406 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

165215406 is a wasteful number, since it uses less digits than its factorization.

165215406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27535906.

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 165215406 is about 12853.6145111015. The cubic root of 165215406 is about 548.7192302906.

Adding to 165215406 its reverse (604512561), we get a palindrome (769727967).

The spelling of 165215406 in words is "one hundred sixty-five million, two hundred fifteen thousand, four hundred six".