25443721 has 2 divisors, whose sum is σ = 25443722. Its totient is φ = 25443720.

The previous prime is 25443709. The next prime is 25443731. The reversal of 25443721 is 12734452.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22848400 + 2595321 = 4780^2 + 1611^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25443721 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25443721.

It is not a weakly prime, because it can be changed into another prime (25443731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12721860 + 12721861.

It is an arithmetic number, because the mean of its divisors is an integer number (12721861).

Almost surely, 2^25443721 is an apocalyptic number.

It is an amenable number.

25443721 is a deficient number, since it is larger than the sum of its proper divisors (1).

25443721 is an equidigital number, since it uses as much as digits as its factorization.

25443721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6720, while the sum is 28.

The square root of 25443721 is about 5044.1769397990. The cubic root of 25443721 is about 294.1215695736.

The spelling of 25443721 in words is "twenty-five million, four hundred forty-three thousand, seven hundred twenty-one".