20268287993 has 2 divisors, whose sum is σ = 20268287994. Its totient is φ = 20268287992.

The previous prime is 20268287951. The next prime is 20268288011. The reversal of 20268287993 is 39978286202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15601758649 + 4666529344 = 124907^2 + 68312^2 .

It is a cyclic number.

It is not a de Polignac number, because 20268287993 - 2⁶ = 20268287929 is a prime.

It is not a weakly prime, because it can be changed into another prime (20268287093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10134143996 + 10134143997.

It is an arithmetic number, because the mean of its divisors is an integer number (10134143997).

Almost surely, 2^20268287993 is an apocalyptic number.

It is an amenable number.

20268287993 is a deficient number, since it is larger than the sum of its proper divisors (1).

20268287993 is an equidigital number, since it uses as much as digits as its factorization.

20268287993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5225472, while the sum is 56.

The spelling of 20268287993 in words is "twenty billion, two hundred sixty-eight million, two hundred eighty-seven thousand, nine hundred ninety-three".