19779609569 has 2 divisors, whose sum is σ = 19779609570. Its totient is φ = 19779609568.

The previous prime is 19779609559. The next prime is 19779609601. The reversal of 19779609569 is 96590697791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19414799569 + 364810000 = 139337^2 + 19100^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19779609569 is a prime.

It is a super-2 number, since 2×19779609569² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 19779609499 and 19779609508.

It is not a weakly prime, because it can be changed into another prime (19779609559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9889804784 + 9889804785.

It is an arithmetic number, because the mean of its divisors is an integer number (9889804785).

Almost surely, 2^19779609569 is an apocalyptic number.

It is an amenable number.

19779609569 is a deficient number, since it is larger than the sum of its proper divisors (1).

19779609569 is an equidigital number, since it uses as much as digits as its factorization.

19779609569 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 57868020, while the sum is 68.

The spelling of 19779609569 in words is "nineteen billion, seven hundred seventy-nine million, six hundred nine thousand, five hundred sixty-nine".