20287239 has 16 divisors (see below), whose sum is σ = 32732928. Its totient is φ = 10910592.

The previous prime is 20287207. The next prime is 20287243. The reversal of 20287239 is 93278202.

It is not a de Polignac number, because 20287239 - 2⁵ = 20287207 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20287249) 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 in 15 ways as a sum of consecutive naturals, for example, 28057 + ... + 28770.

It is an arithmetic number, because the mean of its divisors is an integer number (2045808).

Almost surely, 2^20287239 is an apocalyptic number.

20287239 is a deficient number, since it is larger than the sum of its proper divisors (12445689).

20287239 is a wasteful number, since it uses less digits than its factorization.

20287239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56854.

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 20287239 is about 4504.1357661598. The cubic root of 20287239 is about 272.7350674843.

The spelling of 20287239 in words is "twenty million, two hundred eighty-seven thousand, two hundred thirty-nine".