21034231 has 2 divisors, whose sum is σ = 21034232. Its totient is φ = 21034230.

The previous prime is 21034229. The next prime is 21034249. The reversal of 21034231 is 13243012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21034231 - 2¹ = 21034229 is a prime.

It is a super-2 number, since 2×21034231² = 884877747522722, which contains 22 as substring.

Together with 21034229, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21034201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10517115 + 10517116.

It is an arithmetic number, because the mean of its divisors is an integer number (10517116).

Almost surely, 2^21034231 is an apocalyptic number.

21034231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21034231 is an equidigital number, since it uses as much as digits as its factorization.

21034231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 21034231 is about 4586.3090824758. The cubic root of 21034231 is about 276.0422421867.

Adding to 21034231 its reverse (13243012), we get a palindrome (34277243).

The spelling of 21034231 in words is "twenty-one million, thirty-four thousand, two hundred thirty-one".