26721109 has 2 divisors, whose sum is σ = 26721110. Its totient is φ = 26721108.

The previous prime is 26721073. The next prime is 26721131. The reversal of 26721109 is 90112762.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25220484 + 1500625 = 5022^2 + 1225^2 .

It is a cyclic number.

It is not a de Polignac number, because 26721109 - 2¹⁷ = 26590037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26721179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13360554 + 13360555.

It is an arithmetic number, because the mean of its divisors is an integer number (13360555).

Almost surely, 2^26721109 is an apocalyptic number.

It is an amenable number.

26721109 is a deficient number, since it is larger than the sum of its proper divisors (1).

26721109 is an equidigital number, since it uses as much as digits as its factorization.

26721109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 26721109 is about 5169.2464634606. The cubic root of 26721109 is about 298.9634933412.

The spelling of 26721109 in words is "twenty-six million, seven hundred twenty-one thousand, one hundred nine".