20643914747 has 2 divisors, whose sum is σ = 20643914748. Its totient is φ = 20643914746.

The previous prime is 20643914729. The next prime is 20643914821. The reversal of 20643914747 is 74741934602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20643914747 - 2⁸ = 20643914491 is a prime.

It is not a weakly prime, because it can be changed into another prime (20643916747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10321957373 + 10321957374.

It is an arithmetic number, because the mean of its divisors is an integer number (10321957374).

Almost surely, 2^20643914747 is an apocalyptic number.

20643914747 is a deficient number, since it is larger than the sum of its proper divisors (1).

20643914747 is an equidigital number, since it uses as much as digits as its factorization.

20643914747 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1016064, while the sum is 47.

The spelling of 20643914747 in words is "twenty billion, six hundred forty-three million, nine hundred fourteen thousand, seven hundred forty-seven".