49999998991 has 2 divisors, whose sum is σ = 49999998992. Its totient is φ = 49999998990.

The previous prime is 49999998943. The next prime is 49999999009. The reversal of 49999998991 is 19989999994.

49999998991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 49999998991 - 2⁹ = 49999998479 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 49999998899 and 49999998908.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (49999998901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 24999999495 + 24999999496.

It is an arithmetic number, because the mean of its divisors is an integer number (24999999496).

Almost surely, 2^49999998991 is an apocalyptic number.

49999998991 is a deficient number, since it is larger than the sum of its proper divisors (1).

49999998991 is an equidigital number, since it uses as much as digits as its factorization.

49999998991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1377495072, while the sum is 85.

The spelling of 49999998991 in words is "forty-nine billion, nine hundred ninety-nine million, nine hundred ninety-eight thousand, nine hundred ninety-one".