2021221231 has 2 divisors, whose sum is σ = 2021221232. Its totient is φ = 2021221230.

The previous prime is 2021221199. The next prime is 2021221243. The reversal of 2021221231 is 1321221202.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2021221231 - 2⁵ = 2021221199 is a prime.

It is a super-2 number, since 2×2021221231² = 8170670529290310722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2021221331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010610615 + 1010610616.

It is an arithmetic number, because the mean of its divisors is an integer number (1010610616).

Almost surely, 2^2021221231 is an apocalyptic number.

2021221231 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021221231 is an equidigital number, since it uses as much as digits as its factorization.

2021221231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 2021221231 is about 44957.9940722448. The cubic root of 2021221231 is about 1264.3615604887.

Adding to 2021221231 its reverse (1321221202), we get a palindrome (3342442433).

The spelling of 2021221231 in words is "two billion, twenty-one million, two hundred twenty-one thousand, two hundred thirty-one".