12870721 has 2 divisors, whose sum is σ = 12870722. Its totient is φ = 12870720.

The previous prime is 12870701. The next prime is 12870749. The reversal of 12870721 is 12707821.

It is an a-pointer prime, because the next prime (12870749) can be obtained adding 12870721 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., 12852225 + 18496 = 3585^2 + 136^2 .

It is a cyclic number.

It is not a de Polignac number, because 12870721 - 2¹⁵ = 12837953 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12870721.

It is not a weakly prime, because it can be changed into another prime (12870701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6435360 + 6435361.

It is an arithmetic number, because the mean of its divisors is an integer number (6435361).

Almost surely, 2^12870721 is an apocalyptic number.

It is an amenable number.

12870721 is a deficient number, since it is larger than the sum of its proper divisors (1).

12870721 is an equidigital number, since it uses as much as digits as its factorization.

12870721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1568, while the sum is 28.

The square root of 12870721 is about 3587.5787099379. The cubic root of 12870721 is about 234.3514394331.

The spelling of 12870721 in words is "twelve million, eight hundred seventy thousand, seven hundred twenty-one".