13533209981 has 2 divisors, whose sum is σ = 13533209982. Its totient is φ = 13533209980.

The previous prime is 13533209969. The next prime is 13533209983. The reversal of 13533209981 is 18990233531.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9618705625 + 3914504356 = 98075^2 + 62566^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13533209981 is a prime.

It is a super-2 number, since 2×13533209981² (a number of 21 digits) contains 22 as substring.

Together with 13533209983, 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 (13533209983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6766604990 + 6766604991.

It is an arithmetic number, because the mean of its divisors is an integer number (6766604991).

Almost surely, 2^13533209981 is an apocalyptic number.

It is an amenable number.

13533209981 is a deficient number, since it is larger than the sum of its proper divisors (1).

13533209981 is an equidigital number, since it uses as much as digits as its factorization.

13533209981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 174960, while the sum is 44.

The spelling of 13533209981 in words is "thirteen billion, five hundred thirty-three million, two hundred nine thousand, nine hundred eighty-one".