21834823 has 2 divisors, whose sum is σ = 21834824. Its totient is φ = 21834822.

The previous prime is 21834821. The next prime is 21834833. The reversal of 21834823 is 32843812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21834823 - 2¹ = 21834821 is a prime.

Together with 21834821, it forms a pair of twin primes.

It is equal to p_1379434 and since 21834823 and 1379434 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21834821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10917411 + 10917412.

It is an arithmetic number, because the mean of its divisors is an integer number (10917412).

Almost surely, 2^21834823 is an apocalyptic number.

21834823 is a deficient number, since it is larger than the sum of its proper divisors (1).

21834823 is an equidigital number, since it uses as much as digits as its factorization.

21834823 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9216, while the sum is 31.

The square root of 21834823 is about 4672.7746575242. The cubic root of 21834823 is about 279.5009093857.

The spelling of 21834823 in words is "twenty-one million, eight hundred thirty-four thousand, eight hundred twenty-three".