21834431 has 2 divisors, whose sum is σ = 21834432. Its totient is φ = 21834430.

The previous prime is 21834413. The next prime is 21834433. The reversal of 21834431 is 13443812.

Together with previous prime (21834413) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21834431 is a prime.

It is a super-2 number, since 2×21834431² = 953484754187522, which contains 22 as substring.

Together with 21834433, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21834431.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21834433) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10917215 + 10917216.

It is an arithmetic number, because the mean of its divisors is an integer number (10917216).

Almost surely, 2^21834431 is an apocalyptic number.

21834431 is a deficient number, since it is larger than the sum of its proper divisors (1).

21834431 is an equidigital number, since it uses as much as digits as its factorization.

21834431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2304, while the sum is 26.

The square root of 21834431 is about 4672.7327122360. The cubic root of 21834431 is about 279.4992367515.

The spelling of 21834431 in words is "twenty-one million, eight hundred thirty-four thousand, four hundred thirty-one".