21231010231 has 2 divisors, whose sum is σ = 21231010232. Its totient is φ = 21231010230.

The previous prime is 21231010169. The next prime is 21231010237. The reversal of 21231010231 is 13201013212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21231010231 is a prime.

It is a super-2 number, since 2×21231010231² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21231010237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615505115 + 10615505116.

It is an arithmetic number, because the mean of its divisors is an integer number (10615505116).

Almost surely, 2^21231010231 is an apocalyptic number.

21231010231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231010231 is an equidigital number, since it uses as much as digits as its factorization.

21231010231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21231010231 its reverse (13201013212), we get a palindrome (34432023443).

The spelling of 21231010231 in words is "twenty-one billion, two hundred thirty-one million, ten thousand, two hundred thirty-one".