20618148809 has 2 divisors, whose sum is σ = 20618148810. Its totient is φ = 20618148808.

The previous prime is 20618148781. The next prime is 20618148827. The reversal of 20618148809 is 90884181602.

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., 20603731600 + 14417209 = 143540^2 + 3797^2 .

It is a cyclic number.

It is not a de Polignac number, because 20618148809 - 2⁸ = 20618148553 is a prime.

It is not a weakly prime, because it can be changed into another prime (20618148409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10309074404 + 10309074405.

It is an arithmetic number, because the mean of its divisors is an integer number (10309074405).

Almost surely, 2^20618148809 is an apocalyptic number.

It is an amenable number.

20618148809 is a deficient number, since it is larger than the sum of its proper divisors (1).

20618148809 is an equidigital number, since it uses as much as digits as its factorization.

20618148809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 221184, while the sum is 47.

The spelling of 20618148809 in words is "twenty billion, six hundred eighteen million, one hundred forty-eight thousand, eight hundred nine".