13641857521 has 2 divisors, whose sum is σ = 13641857522. Its totient is φ = 13641857520.

The previous prime is 13641857473. The next prime is 13641857531. The reversal of 13641857521 is 12575814631.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13636400625 + 5456896 = 116775^2 + 2336^2 .

It is a cyclic number.

It is not a de Polignac number, because 13641857521 - 2²³ = 13633468913 is a prime.

It is a super-2 number, since 2×13641857521² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (13641857531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6820928760 + 6820928761.

It is an arithmetic number, because the mean of its divisors is an integer number (6820928761).

Almost surely, 2^13641857521 is an apocalyptic number.

It is an amenable number.

13641857521 is a deficient number, since it is larger than the sum of its proper divisors (1).

13641857521 is an equidigital number, since it uses as much as digits as its factorization.

13641857521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 201600, while the sum is 43.

The spelling of 13641857521 in words is "thirteen billion, six hundred forty-one million, eight hundred fifty-seven thousand, five hundred twenty-one".