26978191 has 2 divisors, whose sum is σ = 26978192. Its totient is φ = 26978190.

The previous prime is 26978131. The next prime is 26978197. The reversal of 26978191 is 19187962.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 26978191 - 2⁹ = 26977679 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26978197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13489095 + 13489096.

It is an arithmetic number, because the mean of its divisors is an integer number (13489096).

Almost surely, 2^26978191 is an apocalyptic number.

26978191 is a deficient number, since it is larger than the sum of its proper divisors (1).

26978191 is an equidigital number, since it uses as much as digits as its factorization.

26978191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 43.

The square root of 26978191 is about 5194.0534267564. The cubic root of 26978191 is about 299.9192041680.

The spelling of 26978191 in words is "twenty-six million, nine hundred seventy-eight thousand, one hundred ninety-one".