20117648779 has 2 divisors, whose sum is σ = 20117648780. Its totient is φ = 20117648778.

The previous prime is 20117648767. The next prime is 20117648827. The reversal of 20117648779 is 97784671102.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20117648779 - 2⁷ = 20117648651 is a prime.

It is not a weakly prime, because it can be changed into another prime (20117648879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10058824389 + 10058824390.

It is an arithmetic number, because the mean of its divisors is an integer number (10058824390).

Almost surely, 2^20117648779 is an apocalyptic number.

20117648779 is a deficient number, since it is larger than the sum of its proper divisors (1).

20117648779 is an equidigital number, since it uses as much as digits as its factorization.

20117648779 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1185408, while the sum is 52.

The spelling of 20117648779 in words is "twenty billion, one hundred seventeen million, six hundred forty-eight thousand, seven hundred seventy-nine".