25221418102561 has 2 divisors, whose sum is σ = 25221418102562. Its totient is φ = 25221418102560.

The previous prime is 25221418102501. The next prime is 25221418102583. The reversal of 25221418102561 is 16520181412252.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23672311776400 + 1549106326161 = 4865420^2 + 1244631^2 .

It is a cyclic number.

It is not a de Polignac number, because 25221418102561 - 2¹¹ = 25221418100513 is a prime.

It is a super-2 number, since 2×25221418102561² (a number of 28 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (25221418102501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12610709051280 + 12610709051281.

It is an arithmetic number, because the mean of its divisors is an integer number (12610709051281).

Almost surely, 2^{25221418102561} is an apocalyptic number.

It is an amenable number.

25221418102561 is a deficient number, since it is larger than the sum of its proper divisors (1).

25221418102561 is an equidigital number, since it uses as much as digits as its factorization.

25221418102561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 76800, while the sum is 40.

The spelling of 25221418102561 in words is "twenty-five trillion, two hundred twenty-one billion, four hundred eighteen million, one hundred two thousand, five hundred sixty-one".