20887 has 2 divisors, whose sum is σ = 20888. Its totient is φ = 20886.

The previous prime is 20879. The next prime is 20897. The reversal of 20887 is 78802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20887 - 2³ = 20879 is a prime.

It is a d-powerful number, because it can be written as 2¹⁴ + 0 + 8² + 8⁴ + 7³ .

20887 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10443 + 10444.

It is an arithmetic number, because the mean of its divisors is an integer number (10444).

2²⁰⁸⁸⁷ is an apocalyptic number.

20887 is a deficient number, since it is larger than the sum of its proper divisors (1).

20887 is an equidigital number, since it uses as much as digits as its factorization.

20887 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 20887 is about 144.5233545141. The cubic root of 20887 is about 27.5396672725.

Subtracting from 20887 its product of nonzero digits (896), we obtain a palindrome (19991).

The spelling of 20887 in words is "twenty thousand, eight hundred eighty-seven".