20686392787 has 2 divisors, whose sum is σ = 20686392788. Its totient is φ = 20686392786.

The previous prime is 20686392737. The next prime is 20686392791. The reversal of 20686392787 is 78729368602.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20686392787 is a prime.

It is not a weakly prime, because it can be changed into another prime (20686392737) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10343196393 + 10343196394.

It is an arithmetic number, because the mean of its divisors is an integer number (10343196394).

Almost surely, 2^20686392787 is an apocalyptic number.

20686392787 is a deficient number, since it is larger than the sum of its proper divisors (1).

20686392787 is an equidigital number, since it uses as much as digits as its factorization.

20686392787 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12192768, while the sum is 58.

The spelling of 20686392787 in words is "twenty billion, six hundred eighty-six million, three hundred ninety-two thousand, seven hundred eighty-seven".