12721361 has 2 divisors, whose sum is σ = 12721362. Its totient is φ = 12721360.

The previous prime is 12721333. The next prime is 12721363. The reversal of 12721361 is 16312721.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9186961 + 3534400 = 3031^2 + 1880^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12721361 is a prime.

Together with 12721363, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p₈₃₂₂₅₃ and since 12721361 and 832253 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (12721363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6360680 + 6360681.

It is an arithmetic number, because the mean of its divisors is an integer number (6360681).

Almost surely, 2^12721361 is an apocalyptic number.

It is an amenable number.

12721361 is a deficient number, since it is larger than the sum of its proper divisors (1).

12721361 is an equidigital number, since it uses as much as digits as its factorization.

12721361 is an evil number, because the sum of its binary digits is even.

The product of its digits is 504, while the sum is 23.

The square root of 12721361 is about 3566.7016976473. The cubic root of 12721361 is about 233.4413891810.

The spelling of 12721361 in words is "twelve million, seven hundred twenty-one thousand, three hundred sixty-one".