20212289 has 4 divisors (see below), whose sum is σ = 20543700. Its totient is φ = 19880880.

The previous prime is 20212271. The next prime is 20212319. The reversal of 20212289 is 98221202.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 984064 + 19228225 = 992^2 + 4385^2 .

It is a cyclic number.

It is not a de Polignac number, because 20212289 - 2⁸ = 20212033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20212259) 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, 165614 + ... + 165735.

It is an arithmetic number, because the mean of its divisors is an integer number (5135925).

Almost surely, 2^20212289 is an apocalyptic number.

It is an amenable number.

20212289 is a deficient number, since it is larger than the sum of its proper divisors (331411).

20212289 is an equidigital number, since it uses as much as digits as its factorization.

20212289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331410.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 20212289 is about 4495.8079362891. The cubic root of 20212289 is about 272.3987851806.

The spelling of 20212289 in words is "twenty million, two hundred twelve thousand, two hundred eighty-nine".