19439958646949 has 2 divisors, whose sum is σ = 19439958646950. Its totient is φ = 19439958646948.

The previous prime is 19439958646937. The next prime is 19439958646967. The reversal of 19439958646949 is 94964685993491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19207340533924 + 232618113025 = 4382618^2 + 482305^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19439958646949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19439958646909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9719979323474 + 9719979323475.

It is an arithmetic number, because the mean of its divisors is an integer number (9719979323475).

Almost surely, 2^{19439958646949} is an apocalyptic number.

It is an amenable number.

19439958646949 is a deficient number, since it is larger than the sum of its proper divisors (1).

19439958646949 is an equidigital number, since it uses as much as digits as its factorization.

19439958646949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16325867520, while the sum is 86.

The spelling of 19439958646949 in words is "nineteen trillion, four hundred thirty-nine billion, nine hundred fifty-eight million, six hundred forty-six thousand, nine hundred forty-nine".