26981909 has 2 divisors, whose sum is σ = 26981910. Its totient is φ = 26981908.

The previous prime is 26981887. The next prime is 26981951. The reversal of 26981909 is 90918962.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26728900 + 253009 = 5170^2 + 503^2 .

It is a cyclic number.

It is not a de Polignac number, because 26981909 - 2²⁰ = 25933333 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 26981909.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26981509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13490954 + 13490955.

It is an arithmetic number, because the mean of its divisors is an integer number (13490955).

Almost surely, 2^26981909 is an apocalyptic number.

It is an amenable number.

26981909 is a deficient number, since it is larger than the sum of its proper divisors (1).

26981909 is an equidigital number, since it uses as much as digits as its factorization.

26981909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69984, while the sum is 44.

The square root of 26981909 is about 5194.4113237209. The cubic root of 26981909 is about 299.9329813257.

The spelling of 26981909 in words is "twenty-six million, nine hundred eighty-one thousand, nine hundred nine".