20308285 has 8 divisors (see below), whose sum is σ = 25803576. Its totient is φ = 15290880.

The previous prime is 20308273. The next prime is 20308291. The reversal of 20308285 is 58280302.

It can be written as a sum of positive squares in 4 ways, for example, as 219961 + 20088324 = 469^2 + 4482^2 .

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

It is not a de Polignac number, because 20308285 - 2⁷ = 20308157 is a prime.

It is a super-3 number, since 3×20308285³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119376 + ... + 119545.

It is an arithmetic number, because the mean of its divisors is an integer number (3225447).

Almost surely, 2^20308285 is an apocalyptic number.

It is an amenable number.

20308285 is a deficient number, since it is larger than the sum of its proper divisors (5495291).

20308285 is a wasteful number, since it uses less digits than its factorization.

20308285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238943.

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 20308285 is about 4506.4714578038. The cubic root of 20308285 is about 272.8293467582.

Adding to 20308285 its reverse (58280302), we get a palindrome (78588587).

The spelling of 20308285 in words is "twenty million, three hundred eight thousand, two hundred eighty-five".