25015644342421 has 2 divisors, whose sum is σ = 25015644342422. Its totient is φ = 25015644342420.

The previous prime is 25015644342419. The next prime is 25015644342497. The reversal of 25015644342421 is 12424344651052.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23614643060100 + 1401001282321 = 4859490^2 + 1183639^2 .

It is a cyclic number.

It is not a de Polignac number, because 25015644342421 - 2¹ = 25015644342419 is a prime.

Together with 25015644342419, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25015644342721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12507822171210 + 12507822171211.

It is an arithmetic number, because the mean of its divisors is an integer number (12507822171211).

Almost surely, 2^{25015644342421} is an apocalyptic number.

It is an amenable number.

25015644342421 is a deficient number, since it is larger than the sum of its proper divisors (1).

25015644342421 is an equidigital number, since it uses as much as digits as its factorization.

25015644342421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 921600, while the sum is 43.

Adding to 25015644342421 its reverse (12424344651052), we get a palindrome (37439988993473).

The spelling of 25015644342421 in words is "twenty-five trillion, fifteen billion, six hundred forty-four million, three hundred forty-two thousand, four hundred twenty-one".