19539169957 has 2 divisors, whose sum is σ = 19539169958. Its totient is φ = 19539169956.

The previous prime is 19539169883. The next prime is 19539170009. The reversal of 19539169957 is 75996193591.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15198204961 + 4340964996 = 123281^2 + 65886^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19539169957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19539160957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9769584978 + 9769584979.

It is an arithmetic number, because the mean of its divisors is an integer number (9769584979).

Almost surely, 2^19539169957 is an apocalyptic number.

It is an amenable number.

19539169957 is a deficient number, since it is larger than the sum of its proper divisors (1).

19539169957 is an equidigital number, since it uses as much as digits as its factorization.

19539169957 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20667150, while the sum is 64.

The spelling of 19539169957 in words is "nineteen billion, five hundred thirty-nine million, one hundred sixty-nine thousand, nine hundred fifty-seven".