21203030231 has 2 divisors, whose sum is σ = 21203030232. Its totient is φ = 21203030230.

The previous prime is 21203030213. The next prime is 21203030267. The reversal of 21203030231 is 13203030212.

Together with previous prime (21203030213) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21203030231 is a prime.

It is a super-2 number, since 2×21203030231² (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 (21203030291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601515115 + 10601515116.

It is an arithmetic number, because the mean of its divisors is an integer number (10601515116).

Almost surely, 2^21203030231 is an apocalyptic number.

21203030231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21203030231 is an equidigital number, since it uses as much as digits as its factorization.

21203030231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 17.

Adding to 21203030231 its reverse (13203030212), we get a palindrome (34406060443).

The spelling of 21203030231 in words is "twenty-one billion, two hundred three million, thirty thousand, two hundred thirty-one".