165556331 has 4 divisors (see below), whose sum is σ = 171265200. Its totient is φ = 159847464.

The previous prime is 165556289. The next prime is 165556333. The reversal of 165556331 is 133655561.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 165556331 - 2⁶ = 165556267 is a prime.

It is a super-2 number, since 2×165556331² = 54817797468363122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 165556291 and 165556300.

It is not an unprimeable number, because it can be changed into a prime (165556333) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2854391 + ... + 2854448.

It is an arithmetic number, because the mean of its divisors is an integer number (42816300).

Almost surely, 2^165556331 is an apocalyptic number.

165556331 is a deficient number, since it is larger than the sum of its proper divisors (5708869).

165556331 is an equidigital number, since it uses as much as digits as its factorization.

165556331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5708868.

The product of its digits is 40500, while the sum is 35.

The square root of 165556331 is about 12866.8695104909. The cubic root of 165556331 is about 549.0964016853.

The spelling of 165556331 in words is "one hundred sixty-five million, five hundred fifty-six thousand, three hundred thirty-one".