165821122 has 8 divisors (see below), whose sum is σ = 259546176. Its totient is φ = 79305732.

The previous prime is 165821107. The next prime is 165821137. The reversal of 165821122 is 221128561.

It is an interprime number because it is at equal distance from previous prime (165821107) and next prime (165821137).

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

It is an unprimeable number.

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, 1802358 + ... + 1802449.

It is an arithmetic number, because the mean of its divisors is an integer number (32443272).

Almost surely, 2^165821122 is an apocalyptic number.

165821122 is a deficient number, since it is larger than the sum of its proper divisors (93725054).

165821122 is a wasteful number, since it uses less digits than its factorization.

165821122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3604832.

The product of its digits is 1920, while the sum is 28.

The square root of 165821122 is about 12877.1550429433. The cubic root of 165821122 is about 549.3889875740.

Adding to 165821122 its reverse (221128561), we get a palindrome (386949683).

The spelling of 165821122 in words is "one hundred sixty-five million, eight hundred twenty-one thousand, one hundred twenty-two".