26878211681 has 4 divisors (see below), whose sum is σ = 27318838164. Its totient is φ = 26437585200.

The previous prime is 26878211597. The next prime is 26878211683. The reversal of 26878211681 is 18611287862.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6147971281 + 20730240400 = 78409^2 + 143980^2 .

It is a cyclic number.

It is not a de Polignac number, because 26878211681 - 2¹⁰ = 26878210657 is a prime.

It is a super-2 number, since 2×26878211681² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (26878211683) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 220313150 + ... + 220313271.

It is an arithmetic number, because the mean of its divisors is an integer number (6829709541).

Almost surely, 2^26878211681 is an apocalyptic number.

It is an amenable number.

26878211681 is a deficient number, since it is larger than the sum of its proper divisors (440626483).

26878211681 is an equidigital number, since it uses as much as digits as its factorization.

26878211681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440626482.

The product of its digits is 516096, while the sum is 50.

The spelling of 26878211681 in words is "twenty-six billion, eight hundred seventy-eight million, two hundred eleven thousand, six hundred eighty-one".