20203891 has 2 divisors, whose sum is σ = 20203892. Its totient is φ = 20203890.

The previous prime is 20203889. The next prime is 20203903. The reversal of 20203891 is 19830202.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20203891 - 2¹ = 20203889 is a prime.

Together with 20203889, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20203811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10101945 + 10101946.

It is an arithmetic number, because the mean of its divisors is an integer number (10101946).

Almost surely, 2^20203891 is an apocalyptic number.

20203891 is a deficient number, since it is larger than the sum of its proper divisors (1).

20203891 is an equidigital number, since it uses as much as digits as its factorization.

20203891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 20203891 is about 4494.8738580743. The cubic root of 20203891 is about 272.3610536485.

The spelling of 20203891 in words is "twenty million, two hundred three thousand, eight hundred ninety-one".