20050404991 has 2 divisors, whose sum is σ = 20050404992. Its totient is φ = 20050404990.

The previous prime is 20050404973. The next prime is 20050405019. The reversal of 20050404991 is 19940405002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20050404991 - 2¹¹ = 20050402943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20050404901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10025202495 + 10025202496.

It is an arithmetic number, because the mean of its divisors is an integer number (10025202496).

Almost surely, 2^20050404991 is an apocalyptic number.

20050404991 is a deficient number, since it is larger than the sum of its proper divisors (1).

20050404991 is an equidigital number, since it uses as much as digits as its factorization.

20050404991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 34.

Adding to 20050404991 its reverse (19940405002), we get a palindrome (39990809993).

The spelling of 20050404991 in words is "twenty billion, fifty million, four hundred four thousand, nine hundred ninety-one".