26390989 has 2 divisors, whose sum is σ = 26390990. Its totient is φ = 26390988.

The previous prime is 26390983. The next prime is 26390999. The reversal of 26390989 is 98909362.

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., 25050025 + 1340964 = 5005^2 + 1158^2 .

It is a cyclic number.

It is not a de Polignac number, because 26390989 - 2¹¹ = 26388941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26390983) 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, 13195494 + 13195495.

It is an arithmetic number, because the mean of its divisors is an integer number (13195495).

Almost surely, 2^26390989 is an apocalyptic number.

It is an amenable number.

26390989 is a deficient number, since it is larger than the sum of its proper divisors (1).

26390989 is an equidigital number, since it uses as much as digits as its factorization.

26390989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 209952, while the sum is 46.

The square root of 26390989 is about 5137.2160748795. The cubic root of 26390989 is about 297.7272288900.

The spelling of 26390989 in words is "twenty-six million, three hundred ninety thousand, nine hundred eighty-nine".