26215136621 has 2 divisors, whose sum is σ = 26215136622. Its totient is φ = 26215136620.

The previous prime is 26215136611. The next prime is 26215136693. The reversal of 26215136621 is 12663151262.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24700837225 + 1514299396 = 157165^2 + 38914^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-26215136621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26215136611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13107568310 + 13107568311.

It is an arithmetic number, because the mean of its divisors is an integer number (13107568311).

Almost surely, 2^26215136621 is an apocalyptic number.

It is an amenable number.

26215136621 is a deficient number, since it is larger than the sum of its proper divisors (1).

26215136621 is an equidigital number, since it uses as much as digits as its factorization.

26215136621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 35.

Adding to 26215136621 its reverse (12663151262), we get a palindrome (38878287883).

The spelling of 26215136621 in words is "twenty-six billion, two hundred fifteen million, one hundred thirty-six thousand, six hundred twenty-one".