12961621 has 2 divisors, whose sum is σ = 12961622. Its totient is φ = 12961620.

The previous prime is 12961607. The next prime is 12961657. The reversal of 12961621 is 12616921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12680721 + 280900 = 3561^2 + 530^2 .

It is an emirp because it is prime and its reverse (12616921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12961621 - 2¹⁹ = 12437333 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12961621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12961601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6480810 + 6480811.

It is an arithmetic number, because the mean of its divisors is an integer number (6480811).

Almost surely, 2^12961621 is an apocalyptic number.

It is an amenable number.

12961621 is a deficient number, since it is larger than the sum of its proper divisors (1).

12961621 is an equidigital number, since it uses as much as digits as its factorization.

12961621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 28.

The square root of 12961621 is about 3600.2251318494. The cubic root of 12961621 is about 234.9018512724.

The spelling of 12961621 in words is "twelve million, nine hundred sixty-one thousand, six hundred twenty-one".