21031230231 has 16 divisors (see below), whose sum is σ = 33989867520. Its totient is φ = 12746199960.

The previous prime is 21031230163. The next prime is 21031230239. The reversal of 21031230231 is 13203213012.

21031230231 is a `hidden beast` number, since 21 + 0 + 312 + 302 + 31 = 666.

It is not a de Polignac number, because 21031230231 - 2⁹ = 21031229719 is a prime.

It is a super-2 number, since 2×21031230231² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21031230239) 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 in 15 ways as a sum of consecutive naturals, for example, 35405815 + ... + 35406408.

It is an arithmetic number, because the mean of its divisors is an integer number (2124366720).

Almost surely, 2^21031230231 is an apocalyptic number.

21031230231 is a deficient number, since it is larger than the sum of its proper divisors (12958637289).

21031230231 is a wasteful number, since it uses less digits than its factorization.

21031230231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70812243 (or 70812237 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21031230231 its reverse (13203213012), we get a palindrome (34234443243).

The spelling of 21031230231 in words is "twenty-one billion, thirty-one million, two hundred thirty thousand, two hundred thirty-one".