20116891 has 2 divisors, whose sum is σ = 20116892. Its totient is φ = 20116890.

The previous prime is 20116871. The next prime is 20116903. The reversal of 20116891 is 19861102.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20116891 - 2⁹ = 20116379 is a prime.

It is not a weakly prime, because it can be changed into another prime (20116841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10058445 + 10058446.

It is an arithmetic number, because the mean of its divisors is an integer number (10058446).

Almost surely, 2^20116891 is an apocalyptic number.

20116891 is a deficient number, since it is larger than the sum of its proper divisors (1).

20116891 is an equidigital number, since it uses as much as digits as its factorization.

20116891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 20116891 is about 4485.1857263663. The cubic root of 20116891 is about 271.9695530727.

Adding to 20116891 its reverse (19861102), we get a palindrome (39977993).

The spelling of 20116891 in words is "twenty million, one hundred sixteen thousand, eight hundred ninety-one".