12616921 has 2 divisors, whose sum is σ = 12616922. Its totient is φ = 12616920.

The previous prime is 12616909. The next prime is 12616927. The reversal of 12616921 is 12961621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7728400 + 4888521 = 2780^2 + 2211^2 .

It is an emirp because it is prime and its reverse (12961621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12616921 - 2²³ = 4228313 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12616921.

It is not a weakly prime, because it can be changed into another prime (12616927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6308460 + 6308461.

It is an arithmetic number, because the mean of its divisors is an integer number (6308461).

Almost surely, 2^12616921 is an apocalyptic number.

It is an amenable number.

12616921 is a deficient number, since it is larger than the sum of its proper divisors (1).

12616921 is an equidigital number, since it uses as much as digits as its factorization.

12616921 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 12616921 is about 3552.0305460398. The cubic root of 12616921 is about 232.8007961715.

The spelling of 12616921 in words is "twelve million, six hundred sixteen thousand, nine hundred twenty-one".