20778119909 has 2 divisors, whose sum is σ = 20778119910. Its totient is φ = 20778119908.

The previous prime is 20778119849. The next prime is 20778119927. The reversal of 20778119909 is 90991187702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14907189025 + 5870930884 = 122095^2 + 76622^2 .

It is a cyclic number.

It is not a de Polignac number, because 20778119909 - 2¹⁶ = 20778054373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20778119939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10389059954 + 10389059955.

It is an arithmetic number, because the mean of its divisors is an integer number (10389059955).

Almost surely, 2^20778119909 is an apocalyptic number.

It is an amenable number.

20778119909 is a deficient number, since it is larger than the sum of its proper divisors (1).

20778119909 is an equidigital number, since it uses as much as digits as its factorization.

20778119909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 571536, while the sum is 53.

The spelling of 20778119909 in words is "twenty billion, seven hundred seventy-eight million, one hundred nineteen thousand, nine hundred nine".