20589281 has 4 divisors (see below), whose sum is σ = 20977812. Its totient is φ = 20200752.

The previous prime is 20589271. The next prime is 20589287. The reversal of 20589281 is 18298502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18298502 = 2 ⋅9149251.

It can be written as a sum of positive squares in 2 ways, for example, as 11833600 + 8755681 = 3440^2 + 2959^2 .

It is a cyclic number.

It is not a de Polignac number, because 20589281 - 2¹⁰ = 20588257 is a prime.

It is a super-2 number, since 2×20589281² = 847836984193922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20589287) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 194186 + ... + 194291.

It is an arithmetic number, because the mean of its divisors is an integer number (5244453).

Almost surely, 2^20589281 is an apocalyptic number.

It is an amenable number.

20589281 is a deficient number, since it is larger than the sum of its proper divisors (388531).

20589281 is an equidigital number, since it uses as much as digits as its factorization.

20589281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 388530.

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 20589281 is about 4537.5412945779. The cubic root of 20589281 is about 274.0819235735.

The spelling of 20589281 in words is "twenty million, five hundred eighty-nine thousand, two hundred eighty-one".