25000721 has 2 divisors, whose sum is σ = 25000722. Its totient is φ = 25000720.

The previous prime is 25000711. The next prime is 25000739. The reversal of 25000721 is 12700052.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12673600 + 12327121 = 3560^2 + 3511^2 .

It is a cyclic number.

It is not a de Polignac number, because 25000721 - 2¹⁰ = 24999697 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25000721.

It is not a weakly prime, because it can be changed into another prime (25000711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12500360 + 12500361.

It is an arithmetic number, because the mean of its divisors is an integer number (12500361).

Almost surely, 2^25000721 is an apocalyptic number.

It is an amenable number.

25000721 is a deficient number, since it is larger than the sum of its proper divisors (1).

25000721 is an equidigital number, since it uses as much as digits as its factorization.

25000721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 140, while the sum is 17.

The square root of 25000721 is about 5000.0720994802. The cubic root of 25000721 is about 292.4045847500.

Adding to 25000721 its reverse (12700052), we get a palindrome (37700773).

The spelling of 25000721 in words is "twenty-five million, seven hundred twenty-one", and thus it is an aban number.