20309868947 has 2 divisors, whose sum is σ = 20309868948. Its totient is φ = 20309868946.

The previous prime is 20309868881. The next prime is 20309868967. The reversal of 20309868947 is 74986890302.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20309868947 - 2¹⁸ = 20309606803 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20309868892 and 20309868901.

It is not a weakly prime, because it can be changed into another prime (20309868967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10154934473 + 10154934474.

It is an arithmetic number, because the mean of its divisors is an integer number (10154934474).

Almost surely, 2^20309868947 is an apocalyptic number.

20309868947 is a deficient number, since it is larger than the sum of its proper divisors (1).

20309868947 is an equidigital number, since it uses as much as digits as its factorization.

20309868947 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5225472, while the sum is 56.

The spelling of 20309868947 in words is "twenty billion, three hundred nine million, eight hundred sixty-eight thousand, nine hundred forty-seven".