12501721 has 2 divisors, whose sum is σ = 12501722. Its totient is φ = 12501720.

The previous prime is 12501707. The next prime is 12501733. The reversal of 12501721 is 12710521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7639696 + 4862025 = 2764^2 + 2205^2 .

It is an emirp because it is prime and its reverse (12710521) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12501721 - 2¹³ = 12493529 is a prime.

It is not a weakly prime, because it can be changed into another prime (12501821) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6250860 + 6250861.

It is an arithmetic number, because the mean of its divisors is an integer number (6250861).

Almost surely, 2^12501721 is an apocalyptic number.

It is an amenable number.

12501721 is a deficient number, since it is larger than the sum of its proper divisors (1).

12501721 is an equidigital number, since it uses as much as digits as its factorization.

12501721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 140, while the sum is 19.

The square root of 12501721 is about 3535.7772837100. Note that the first 3 decimals coincide. The cubic root of 12501721 is about 232.0900920910.

The spelling of 12501721 in words is "twelve million, five hundred one thousand, seven hundred twenty-one".