165621121067 has 4 divisors (see below), whose sum is σ = 165622237320. Its totient is φ = 165620004816.

The previous prime is 165621121049. The next prime is 165621121069. The reversal of 165621121067 is 760121126561.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 760121126561 = 853 ⋅891115037.

It is a cyclic number.

It is not a de Polignac number, because 165621121067 - 2¹⁴ = 165621104683 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 165621121067.

It is not an unprimeable number, because it can be changed into a prime (165621121069) 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, 293858 + ... + 646215.

It is an arithmetic number, because the mean of its divisors is an integer number (41405559330).

Almost surely, 2^165621121067 is an apocalyptic number.

165621121067 is a deficient number, since it is larger than the sum of its proper divisors (1116253).

165621121067 is an equidigital number, since it uses as much as digits as its factorization.

165621121067 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1116252.

The product of its (nonzero) digits is 30240, while the sum is 38.

The spelling of 165621121067 in words is "one hundred sixty-five billion, six hundred twenty-one million, one hundred twenty-one thousand, sixty-seven".