21152543164165 has 16 divisors (see below), whose sum is σ = 29009390273280. Its totient is φ = 14504506917120.

The previous prime is 21152543164157. The next prime is 21152543164261. The reversal of 21152543164165 is 56146134525112.

It is not a de Polignac number, because 21152543164165 - 2³ = 21152543164157 is a prime.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 3744621 + ... + 7505149.

It is an arithmetic number, because the mean of its divisors is an integer number (1813086892080).

Almost surely, 2^{21152543164165} is an apocalyptic number.

It is an amenable number.

21152543164165 is a deficient number, since it is larger than the sum of its proper divisors (7856847109115).

21152543164165 is a wasteful number, since it uses less digits than its factorization.

21152543164165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3921252.

The product of its digits is 864000, while the sum is 46.

Adding to 21152543164165 its reverse (56146134525112), we get a palindrome (77298677689277).

The spelling of 21152543164165 in words is "twenty-one trillion, one hundred fifty-two billion, five hundred forty-three million, one hundred sixty-four thousand, one hundred sixty-five".