20289287 has 2 divisors, whose sum is σ = 20289288. Its totient is φ = 20289286.

The previous prime is 20289281. The next prime is 20289293. The reversal of 20289287 is 78298202.

It is a balanced prime because it is at equal distance from previous prime (20289281) and next prime (20289293).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20289287 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20289287.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20289281) 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, 10144643 + 10144644.

It is an arithmetic number, because the mean of its divisors is an integer number (10144644).

Almost surely, 2^20289287 is an apocalyptic number.

20289287 is a deficient number, since it is larger than the sum of its proper divisors (1).

20289287 is an equidigital number, since it uses as much as digits as its factorization.

20289287 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32256, while the sum is 38.

The square root of 20289287 is about 4504.3631070330. The cubic root of 20289287 is about 272.7442447249.

The spelling of 20289287 in words is "twenty million, two hundred eighty-nine thousand, two hundred eighty-seven".