20135887 has 2 divisors, whose sum is σ = 20135888. Its totient is φ = 20135886.

The previous prime is 20135873. The next prime is 20135893. The reversal of 20135887 is 78853102.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20135887 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20135827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10067943 + 10067944.

It is an arithmetic number, because the mean of its divisors is an integer number (10067944).

Almost surely, 2^20135887 is an apocalyptic number.

20135887 is a deficient number, since it is larger than the sum of its proper divisors (1).

20135887 is an equidigital number, since it uses as much as digits as its factorization.

20135887 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 20135887 is about 4487.3028647507. The cubic root of 20135887 is about 272.0551313781.

Adding to 20135887 its reverse (78853102), we get a palindrome (98988989).

The spelling of 20135887 in words is "twenty million, one hundred thirty-five thousand, eight hundred eighty-seven".