16541312031521 has 2 divisors, whose sum is σ = 16541312031522. Its totient is φ = 16541312031520.

The previous prime is 16541312031473. The next prime is 16541312031523. The reversal of 16541312031521 is 12513021314561.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16207186414225 + 334125617296 = 4025815^2 + 578036^2 .

It is an emirp because it is prime and its reverse (12513021314561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16541312031521 - 2⁶ = 16541312031457 is a prime.

Together with 16541312031523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (16541312031523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8270656015760 + 8270656015761.

It is an arithmetic number, because the mean of its divisors is an integer number (8270656015761).

Almost surely, 2^{16541312031521} is an apocalyptic number.

It is an amenable number.

16541312031521 is a deficient number, since it is larger than the sum of its proper divisors (1).

16541312031521 is an equidigital number, since it uses as much as digits as its factorization.

16541312031521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21600, while the sum is 35.

The spelling of 16541312031521 in words is "sixteen trillion, five hundred forty-one billion, three hundred twelve million, thirty-one thousand, five hundred twenty-one".