26978197213439 has 4 divisors (see below), whose sum is σ = 26997344267520. Its totient is φ = 26959050159360.

The previous prime is 26978197213421. The next prime is 26978197213447. The reversal of 26978197213439 is 93431279187962.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-26978197213439 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26978197263439) 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, 9573524927 + ... + 9573527744.

It is an arithmetic number, because the mean of its divisors is an integer number (6749336066880).

Almost surely, 2^{26978197213439} is an apocalyptic number.

26978197213439 is a deficient number, since it is larger than the sum of its proper divisors (19147054081).

26978197213439 is a wasteful number, since it uses less digits than its factorization.

26978197213439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19147054080.

The product of its digits is 246903552, while the sum is 71.

The spelling of 26978197213439 in words is "twenty-six trillion, nine hundred seventy-eight billion, one hundred ninety-seven million, two hundred thirteen thousand, four hundred thirty-nine".