26621809 has 2 divisors, whose sum is σ = 26621810. Its totient is φ = 26621808.

The previous prime is 26621807. The next prime is 26621843. The reversal of 26621809 is 90812662.

It is a happy number.

It is an a-pointer prime, because the next prime (26621843) can be obtained adding 26621809 to its sum of digits (34).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25806400 + 815409 = 5080^2 + 903^2 .

It is a cyclic number.

It is not a de Polignac number, because 26621809 - 2¹ = 26621807 is a prime.

Together with 26621807, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (26621801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13310904 + 13310905.

It is an arithmetic number, because the mean of its divisors is an integer number (13310905).

Almost surely, 2^26621809 is an apocalyptic number.

It is an amenable number.

26621809 is a deficient number, since it is larger than the sum of its proper divisors (1).

26621809 is an equidigital number, since it uses as much as digits as its factorization.

26621809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 26621809 is about 5159.6326419620. The cubic root of 26621809 is about 298.5927012831.

The spelling of 26621809 in words is "twenty-six million, six hundred twenty-one thousand, eight hundred nine".