26540005623821 has 2 divisors, whose sum is σ = 26540005623822. Its totient is φ = 26540005623820.

The previous prime is 26540005623799. The next prime is 26540005623869. The reversal of 26540005623821 is 12832650004562.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17667268530025 + 8872737093796 = 4203245^2 + 2978714^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-26540005623821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26540005623871) 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, 13270002811910 + 13270002811911.

It is an arithmetic number, because the mean of its divisors is an integer number (13270002811911).

Almost surely, 2^{26540005623821} is an apocalyptic number.

It is an amenable number.

26540005623821 is a deficient number, since it is larger than the sum of its proper divisors (1).

26540005623821 is an equidigital number, since it uses as much as digits as its factorization.

26540005623821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 691200, while the sum is 44.

The spelling of 26540005623821 in words is "twenty-six trillion, five hundred forty billion, five million, six hundred twenty-three thousand, eight hundred twenty-one".