50998991 has 2 divisors, whose sum is σ = 50998992. Its totient is φ = 50998990.

The previous prime is 50998979. The next prime is 50999033. The reversal of 50998991 is 19989905.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-50998991 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (50998921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25499495 + 25499496.

It is an arithmetic number, because the mean of its divisors is an integer number (25499496).

Almost surely, 2^50998991 is an apocalyptic number.

50998991 is a deficient number, since it is larger than the sum of its proper divisors (1).

50998991 is an equidigital number, since it uses as much as digits as its factorization.

50998991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 262440, while the sum is 50.

The square root of 50998991 is about 7141.3577840632. The cubic root of 50998991 is about 370.8405312859.

The spelling of 50998991 in words is "fifty million, nine hundred ninety-eight thousand, nine hundred ninety-one".