26978197 has 2 divisors, whose sum is σ = 26978198. Its totient is φ = 26978196.

The previous prime is 26978191. The next prime is 26978213. The reversal of 26978197 is 79187962.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21150801 + 5827396 = 4599^2 + 2414^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-26978197 is a prime.

It is a super-2 number, since 2×26978197² = 1455646226741618, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 26978197.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26978191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13489098 + 13489099.

It is an arithmetic number, because the mean of its divisors is an integer number (13489099).

Almost surely, 2^26978197 is an apocalyptic number.

It is an amenable number.

26978197 is a deficient number, since it is larger than the sum of its proper divisors (1).

26978197 is an equidigital number, since it uses as much as digits as its factorization.

26978197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 381024, while the sum is 49.

The square root of 26978197 is about 5194.0540043400. The cubic root of 26978197 is about 299.9192264022.

The spelling of 26978197 in words is "twenty-six million, nine hundred seventy-eight thousand, one hundred ninety-seven".