26981509 has 2 divisors, whose sum is σ = 26981510. Its totient is φ = 26981508.

The previous prime is 26981497. The next prime is 26981519. The reversal of 26981509 is 90518962.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26040609 + 940900 = 5103^2 + 970^2 .

It is a cyclic number.

It is not a de Polignac number, because 26981509 - 2¹⁵ = 26948741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26981519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13490754 + 13490755.

It is an arithmetic number, because the mean of its divisors is an integer number (13490755).

Almost surely, 2^26981509 is an apocalyptic number.

It is an amenable number.

26981509 is a deficient number, since it is larger than the sum of its proper divisors (1).

26981509 is an equidigital number, since it uses as much as digits as its factorization.

26981509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38880, while the sum is 40.

The square root of 26981509 is about 5194.3728206589. The cubic root of 26981509 is about 299.9314991748.

The spelling of 26981509 in words is "twenty-six million, nine hundred eighty-one thousand, five hundred nine".