19806704647 has 2 divisors, whose sum is σ = 19806704648. Its totient is φ = 19806704646.

The previous prime is 19806704597. The next prime is 19806704657. The reversal of 19806704647 is 74640760891.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19806704647 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19806704594 and 19806704603.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19806704657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9903352323 + 9903352324.

It is an arithmetic number, because the mean of its divisors is an integer number (9903352324).

Almost surely, 2^19806704647 is an apocalyptic number.

19806704647 is a deficient number, since it is larger than the sum of its proper divisors (1).

19806704647 is an equidigital number, since it uses as much as digits as its factorization.

19806704647 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2032128, while the sum is 52.

The spelling of 19806704647 in words is "nineteen billion, eight hundred six million, seven hundred four thousand, six hundred forty-seven".