20635231 has 2 divisors, whose sum is σ = 20635232. Its totient is φ = 20635230.

The previous prime is 20635213. The next prime is 20635261. The reversal of 20635231 is 13253602.

Together with previous prime (20635213) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20635231 - 2⁷ = 20635103 is a prime.

It is a super-4 number, since 4×20635231⁴ (a number of 30 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20635201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10317615 + 10317616.

It is an arithmetic number, because the mean of its divisors is an integer number (10317616).

Almost surely, 2^20635231 is an apocalyptic number.

20635231 is a deficient number, since it is larger than the sum of its proper divisors (1).

20635231 is an equidigital number, since it uses as much as digits as its factorization.

20635231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 22.

The square root of 20635231 is about 4542.6017875222. The cubic root of 20635231 is about 274.2856656255.

Adding to 20635231 its reverse (13253602), we get a palindrome (33888833).

The spelling of 20635231 in words is "twenty million, six hundred thirty-five thousand, two hundred thirty-one".