16545120539021 has 2 divisors, whose sum is σ = 16545120539022. Its totient is φ = 16545120539020.

The previous prime is 16545120538951. The next prime is 16545120539023. The reversal of 16545120539021 is 12093502154561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12906415502500 + 3638705036521 = 3592550^2 + 1907539^2 .

It is an emirp because it is prime and its reverse (12093502154561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16545120539021 - 2³⁴ = 16527940669837 is a prime.

Together with 16545120539023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16545120539023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8272560269510 + 8272560269511.

It is an arithmetic number, because the mean of its divisors is an integer number (8272560269511).

Almost surely, 2^{16545120539021} is an apocalyptic number.

It is an amenable number.

16545120539021 is a deficient number, since it is larger than the sum of its proper divisors (1).

16545120539021 is an equidigital number, since it uses as much as digits as its factorization.

16545120539021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324000, while the sum is 44.

The spelling of 16545120539021 in words is "sixteen trillion, five hundred forty-five billion, one hundred twenty million, five hundred thirty-nine thousand, twenty-one".