20201231 has 2 divisors, whose sum is σ = 20201232. Its totient is φ = 20201230.

The previous prime is 20201227. The next prime is 20201239. The reversal of 20201231 is 13210202.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20201231 - 2² = 20201227 is a prime.

It is a super-2 number, since 2×20201231² = 816179467830722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20201239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10100615 + 10100616.

It is an arithmetic number, because the mean of its divisors is an integer number (10100616).

Almost surely, 2^20201231 is an apocalyptic number.

20201231 is a deficient number, since it is larger than the sum of its proper divisors (1).

20201231 is an equidigital number, since it uses as much as digits as its factorization.

20201231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 20201231 is about 4494.5779557151. The cubic root of 20201231 is about 272.3491003041.

Adding to 20201231 its reverse (13210202), we get a palindrome (33411433).

The spelling of 20201231 in words is "twenty million, two hundred one thousand, two hundred thirty-one".