2050205551991 has 4 divisors (see below), whose sum is σ = 2065855976184. Its totient is φ = 2034555127800.

The previous prime is 2050205551799. The next prime is 2050205552093. The reversal of 2050205551991 is 1991555020502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2050205551991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2050205551291) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7825211900 + ... + 7825212161.

It is an arithmetic number, because the mean of its divisors is an integer number (516463994046).

Almost surely, 2^{2050205551991} is an apocalyptic number.

2050205551991 is a deficient number, since it is larger than the sum of its proper divisors (15650424193).

2050205551991 is a wasteful number, since it uses less digits than its factorization.

2050205551991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15650424192.

The product of its (nonzero) digits is 202500, while the sum is 44.

The spelling of 2050205551991 in words is "two trillion, fifty billion, two hundred five million, five hundred fifty-one thousand, nine hundred ninety-one".