25168000021 has 2 divisors, whose sum is σ = 25168000022. Its totient is φ = 25168000020.

The previous prime is 25168000009. The next prime is 25168000057. The reversal of 25168000021 is 12000086152.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14953865796 + 10214134225 = 122286^2 + 101065^2 .

It is a cyclic number.

It is not a de Polignac number, because 25168000021 - 2⁹ = 25167999509 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25168000021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25168001021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12584000010 + 12584000011.

It is an arithmetic number, because the mean of its divisors is an integer number (12584000011).

Almost surely, 2^25168000021 is an apocalyptic number.

It is an amenable number.

25168000021 is a deficient number, since it is larger than the sum of its proper divisors (1).

25168000021 is an equidigital number, since it uses as much as digits as its factorization.

25168000021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 960, while the sum is 25.

Adding to 25168000021 its reverse (12000086152), we get a palindrome (37168086173).

The spelling of 25168000021 in words is "twenty-five billion, one hundred sixty-eight million, twenty-one", and thus it is an aban number.