26401251517 has 2 divisors, whose sum is σ = 26401251518. Its totient is φ = 26401251516.

The previous prime is 26401251497. The next prime is 26401251529. The reversal of 26401251517 is 71515210462.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23711688196 + 2689563321 = 153986^2 + 51861^2 .

It is a cyclic number.

It is not a de Polignac number, because 26401251517 - 2⁷ = 26401251389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26401251817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13200625758 + 13200625759.

It is an arithmetic number, because the mean of its divisors is an integer number (13200625759).

Almost surely, 2^26401251517 is an apocalyptic number.

It is an amenable number.

26401251517 is a deficient number, since it is larger than the sum of its proper divisors (1).

26401251517 is an equidigital number, since it uses as much as digits as its factorization.

26401251517 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16800, while the sum is 34.

Adding to 26401251517 its reverse (71515210462), we get a palindrome (97916461979).

The spelling of 26401251517 in words is "twenty-six billion, four hundred one million, two hundred fifty-one thousand, five hundred seventeen".