20636665667 has 2 divisors, whose sum is σ = 20636665668. Its totient is φ = 20636665666.

The previous prime is 20636665661. The next prime is 20636665717. The reversal of 20636665667 is 76656663602.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20636665667 is a prime.

It is not a weakly prime, because it can be changed into another prime (20636665661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10318332833 + 10318332834.

It is an arithmetic number, because the mean of its divisors is an integer number (10318332834).

Almost surely, 2^20636665667 is an apocalyptic number.

20636665667 is a deficient number, since it is larger than the sum of its proper divisors (1).

20636665667 is an equidigital number, since it uses as much as digits as its factorization.

20636665667 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9797760, while the sum is 53.

The spelling of 20636665667 in words is "twenty billion, six hundred thirty-six million, six hundred sixty-five thousand, six hundred sixty-seven".