20199638957 has 2 divisors, whose sum is σ = 20199638958. Its totient is φ = 20199638956.

The previous prime is 20199638911. The next prime is 20199638981. The reversal of 20199638957 is 75983699102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20190704836 + 8934121 = 142094^2 + 2989^2 .

It is a cyclic number.

It is not a de Polignac number, because 20199638957 - 2³⁴ = 3019769773 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20199638896 and 20199638905.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20199638057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10099819478 + 10099819479.

It is an arithmetic number, because the mean of its divisors is an integer number (10099819479).

Almost surely, 2^20199638957 is an apocalyptic number.

It is an amenable number.

20199638957 is a deficient number, since it is larger than the sum of its proper divisors (1).

20199638957 is an equidigital number, since it uses as much as digits as its factorization.

20199638957 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7348320, while the sum is 59.

The spelling of 20199638957 in words is "twenty billion, one hundred ninety-nine million, six hundred thirty-eight thousand, nine hundred fifty-seven".