165020050201621 has 4 divisors (see below), whose sum is σ = 165020494905100. Its totient is φ = 165019605498144.

The previous prime is 165020050201543. The next prime is 165020050201667. The reversal of 165020050201621 is 126102050020561.

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

It can be written as a sum of positive squares in 2 ways, for example, as 107982648760900 + 57037401440721 = 10391470^2 + 7552311^2 .

It is a cyclic number.

It is not a de Polignac number, because 165020050201621 - 2⁷ = 165020050201493 is a prime.

It is a super-3 number, since 3×165020050201621³ (a number of 44 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165020050201681) 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 3 ways as a sum of consecutive naturals, for example, 221794656 + ... + 222537433.

It is an arithmetic number, because the mean of its divisors is an integer number (41255123726275).

Almost surely, 2^{165020050201621} is an apocalyptic number.

It is an amenable number.

165020050201621 is a deficient number, since it is larger than the sum of its proper divisors (444703479).

165020050201621 is an equidigital number, since it uses as much as digits as its factorization.

165020050201621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 444703478.

The product of its (nonzero) digits is 7200, while the sum is 31.

The spelling of 165020050201621 in words is "one hundred sixty-five trillion, twenty billion, fifty million, two hundred one thousand, six hundred twenty-one".