20001243391 has 2 divisors, whose sum is σ = 20001243392. Its totient is φ = 20001243390.

The previous prime is 20001243373. The next prime is 20001243473. The reversal of 20001243391 is 19334210002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20001243391 - 2⁷ = 20001243263 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20001243331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000621695 + 10000621696.

It is an arithmetic number, because the mean of its divisors is an integer number (10000621696).

Almost surely, 2^20001243391 is an apocalyptic number.

20001243391 is a deficient number, since it is larger than the sum of its proper divisors (1).

20001243391 is an equidigital number, since it uses as much as digits as its factorization.

20001243391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 25.

Adding to 20001243391 its reverse (19334210002), we get a palindrome (39335453393).

The spelling of 20001243391 in words is "twenty billion, one million, two hundred forty-three thousand, three hundred ninety-one".