20842289 has 8 divisors (see below), whose sum is σ = 23766120. Its totient is φ = 18107136.

The previous prime is 20842279. The next prime is 20842319. The reversal of 20842289 is 98224802.

It can be written as a sum of positive squares in 4 ways, for example, as 6150400 + 14691889 = 2480^2 + 3833^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20842289 - 2²⁴ = 4065073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20842219) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46934 + ... + 47375.

It is an arithmetic number, because the mean of its divisors is an integer number (2970765).

Almost surely, 2^20842289 is an apocalyptic number.

It is an amenable number.

20842289 is a deficient number, since it is larger than the sum of its proper divisors (2923831).

20842289 is a wasteful number, since it uses less digits than its factorization.

20842289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94339.

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 20842289 is about 4565.3355845984. The cubic root of 20842289 is about 275.2000263726.

The spelling of 20842289 in words is "twenty million, eight hundred forty-two thousand, two hundred eighty-nine".