231025021 has 2 divisors, whose sum is σ = 231025022. Its totient is φ = 231025020.

The previous prime is 231025007. The next prime is 231025031. The reversal of 231025021 is 120520132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 214944921 + 16080100 = 14661^2 + 4010^2 .

It is a cyclic number.

It is not a de Polignac number, because 231025021 - 2¹¹ = 231022973 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 231024986 and 231025004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231025031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115512510 + 115512511.

It is an arithmetic number, because the mean of its divisors is an integer number (115512511).

Almost surely, 2^231025021 is an apocalyptic number.

It is an amenable number.

231025021 is a deficient number, since it is larger than the sum of its proper divisors (1).

231025021 is an equidigital number, since it uses as much as digits as its factorization.

231025021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 231025021 is about 15199.5072617503. The cubic root of 231025021 is about 613.6013966531.

Adding to 231025021 its reverse (120520132), we get a palindrome (351545153).

The spelling of 231025021 in words is "two hundred thirty-one million, twenty-five thousand, twenty-one".