20107691 has 2 divisors, whose sum is σ = 20107692. Its totient is φ = 20107690.

The previous prime is 20107679. The next prime is 20107693. The reversal of 20107691 is 19670102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20107691 - 2¹⁸ = 19845547 is a prime.

Together with 20107693, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20107691.

It is not a weakly prime, because it can be changed into another prime (20107693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10053845 + 10053846.

It is an arithmetic number, because the mean of its divisors is an integer number (10053846).

Almost surely, 2^20107691 is an apocalyptic number.

20107691 is a deficient number, since it is larger than the sum of its proper divisors (1).

20107691 is an equidigital number, since it uses as much as digits as its factorization.

20107691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 756, while the sum is 26.

The square root of 20107691 is about 4484.1600105259. The cubic root of 20107691 is about 271.9280870659.

Adding to 20107691 its reverse (19670102), we get a palindrome (39777793).

The spelling of 20107691 in words is "twenty million, one hundred seven thousand, six hundred ninety-one".