25312556221 has 2 divisors, whose sum is σ = 25312556222. Its totient is φ = 25312556220.

The previous prime is 25312556197. The next prime is 25312556233. The reversal of 25312556221 is 12265521352.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16961155225 + 8351400996 = 130235^2 + 91386^2 .

It is a cyclic number.

It is not a de Polignac number, because 25312556221 - 2⁵ = 25312556189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25312556251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12656278110 + 12656278111.

It is an arithmetic number, because the mean of its divisors is an integer number (12656278111).

Almost surely, 2^25312556221 is an apocalyptic number.

It is an amenable number.

25312556221 is a deficient number, since it is larger than the sum of its proper divisors (1).

25312556221 is an equidigital number, since it uses as much as digits as its factorization.

25312556221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36000, while the sum is 34.

The spelling of 25312556221 in words is "twenty-five billion, three hundred twelve million, five hundred fifty-six thousand, two hundred twenty-one".