26215643569 has 2 divisors, whose sum is σ = 26215643570. Its totient is φ = 26215643568.

The previous prime is 26215643563. The next prime is 26215643591. The reversal of 26215643569 is 96534651262.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21791664400 + 4423979169 = 147620^2 + 66513^2 .

It is a cyclic number.

It is not a de Polignac number, because 26215643569 - 2²¹ = 26213546417 is a prime.

It is a super-2 number, since 2×26215643569² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (26215643563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13107821784 + 13107821785.

It is an arithmetic number, because the mean of its divisors is an integer number (13107821785).

Almost surely, 2^26215643569 is an apocalyptic number.

It is an amenable number.

26215643569 is a deficient number, since it is larger than the sum of its proper divisors (1).

26215643569 is an equidigital number, since it uses as much as digits as its factorization.

26215643569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2332800, while the sum is 49.

The spelling of 26215643569 in words is "twenty-six billion, two hundred fifteen million, six hundred forty-three thousand, five hundred sixty-nine".