231202021 has 2 divisors, whose sum is σ = 231202022. Its totient is φ = 231202020.

The previous prime is 231202019. The next prime is 231202067. The reversal of 231202021 is 120202132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 230584225 + 617796 = 15185^2 + 786^2 .

It is a cyclic number.

It is not a de Polignac number, because 231202021 - 2¹ = 231202019 is a prime.

Together with 231202019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 231201992 and 231202010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231202121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115601010 + 115601011.

It is an arithmetic number, because the mean of its divisors is an integer number (115601011).

Almost surely, 2^231202021 is an apocalyptic number.

It is an amenable number.

231202021 is a deficient number, since it is larger than the sum of its proper divisors (1).

231202021 is an equidigital number, since it uses as much as digits as its factorization.

231202021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 231202021 is about 15205.3287041090. The cubic root of 231202021 is about 613.7580603800.

Adding to 231202021 its reverse (120202132), we get a palindrome (351404153).

The spelling of 231202021 in words is "two hundred thirty-one million, two hundred two thousand, twenty-one".