165583649021 has 8 divisors (see below), whose sum is σ = 189244896960. Its totient is φ = 141924011328.

The previous prime is 165583648963. The next prime is 165583649069. The reversal of 165583649021 is 120946385561.

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

It is a cyclic number.

It is not a de Polignac number, because 165583649021 - 2¹⁰ = 165583647997 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165583649221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 173516 + ... + 601061.

It is an arithmetic number, because the mean of its divisors is an integer number (23655612120).

Almost surely, 2^165583649021 is an apocalyptic number.

It is an amenable number.

165583649021 is a deficient number, since it is larger than the sum of its proper divisors (23661247939).

165583649021 is an equidigital number, since it uses as much as digits as its factorization.

165583649021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 805123.

The product of its (nonzero) digits is 1555200, while the sum is 50.

The spelling of 165583649021 in words is "one hundred sixty-five billion, five hundred eighty-three million, six hundred forty-nine thousand, twenty-one".