20105287 has 8 divisors (see below), whose sum is σ = 21383600. Its totient is φ = 18849024.

The previous prime is 20105273. The next prime is 20105303. The reversal of 20105287 is 78250102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20105287 - 2¹⁵ = 20072519 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20105227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3612 + ... + 7297.

It is an arithmetic number, because the mean of its divisors is an integer number (2672950).

Almost surely, 2^20105287 is an apocalyptic number.

20105287 is a deficient number, since it is larger than the sum of its proper divisors (1278313).

20105287 is a wasteful number, since it uses less digits than its factorization.

20105287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11025.

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 20105287 is about 4483.8919478507. The cubic root of 20105287 is about 271.9172497338.

Adding to 20105287 its reverse (78250102), we get a palindrome (98355389).

The spelling of 20105287 in words is "twenty million, one hundred five thousand, two hundred eighty-seven".