13281661 has 2 divisors, whose sum is σ = 13281662. Its totient is φ = 13281660.

The previous prime is 13281647. The next prime is 13281689. The reversal of 13281661 is 16618231.

It is an a-pointer prime, because the next prime (13281689) can be obtained adding 13281661 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10201636 + 3080025 = 3194^2 + 1755^2 .

It is a cyclic number.

It is not a de Polignac number, because 13281661 - 2⁵ = 13281629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13281691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6640830 + 6640831.

It is an arithmetic number, because the mean of its divisors is an integer number (6640831).

Almost surely, 2^13281661 is an apocalyptic number.

It is an amenable number.

13281661 is a deficient number, since it is larger than the sum of its proper divisors (1).

13281661 is an equidigital number, since it uses as much as digits as its factorization.

13281661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 28.

The square root of 13281661 is about 3644.4013225769. The cubic root of 13281661 is about 236.8195021089.

Adding to 13281661 its reverse (16618231), we get a palindrome (29899892).

The spelling of 13281661 in words is "thirteen million, two hundred eighty-one thousand, six hundred sixty-one".