13331204221661 has 2 divisors, whose sum is σ = 13331204221662. Its totient is φ = 13331204221660.

The previous prime is 13331204221627. The next prime is 13331204221747. The reversal of 13331204221661 is 16612240213331.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7639668360025 + 5691535861636 = 2763995^2 + 2385694^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13331204221661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13331204221861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6665602110830 + 6665602110831.

It is an arithmetic number, because the mean of its divisors is an integer number (6665602110831).

Almost surely, 2^{13331204221661} is an apocalyptic number.

It is an amenable number.

13331204221661 is a deficient number, since it is larger than the sum of its proper divisors (1).

13331204221661 is an equidigital number, since it uses as much as digits as its factorization.

13331204221661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 35.

Adding to 13331204221661 its reverse (16612240213331), we get a palindrome (29943444434992).

The spelling of 13331204221661 in words is "thirteen trillion, three hundred thirty-one billion, two hundred four million, two hundred twenty-one thousand, six hundred sixty-one".