19766786009 has 2 divisors, whose sum is σ = 19766786010. Its totient is φ = 19766786008.

The previous prime is 19766785981. The next prime is 19766786087. The reversal of 19766786009 is 90068766791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12460810384 + 7305975625 = 111628^2 + 85475^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19766786009 is a prime.

It is not a weakly prime, because it can be changed into another prime (19766786909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9883393004 + 9883393005.

It is an arithmetic number, because the mean of its divisors is an integer number (9883393005).

Almost surely, 2^19766786009 is an apocalyptic number.

It is an amenable number.

19766786009 is a deficient number, since it is larger than the sum of its proper divisors (1).

19766786009 is an equidigital number, since it uses as much as digits as its factorization.

19766786009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6858432, while the sum is 59.

The spelling of 19766786009 in words is "nineteen billion, seven hundred sixty-six million, seven hundred eighty-six thousand, nine".