20200891 has 2 divisors, whose sum is σ = 20200892. Its totient is φ = 20200890.

The previous prime is 20200889. The next prime is 20200903. The reversal of 20200891 is 19800202.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20200891 - 2¹ = 20200889 is a prime.

Together with 20200889, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20200801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10100445 + 10100446.

It is an arithmetic number, because the mean of its divisors is an integer number (10100446).

Almost surely, 2^20200891 is an apocalyptic number.

20200891 is a deficient number, since it is larger than the sum of its proper divisors (1).

20200891 is an equidigital number, since it uses as much as digits as its factorization.

20200891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 20200891 is about 4494.5401322049. The cubic root of 20200891 is about 272.3475723574.

Subtracting from 20200891 its reverse (19800202), we obtain a square (400689 = 633²).

The spelling of 20200891 in words is "twenty million, two hundred thousand, eight hundred ninety-one".