21024313 has 2 divisors, whose sum is σ = 21024314. Its totient is φ = 21024312.

The previous prime is 21024299. The next prime is 21024331. The reversal of 21024313 is 31342012.

It is a happy number.

Together with next prime (21024331) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20766249 + 258064 = 4557^2 + 508^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21024313 is a prime.

It is not a weakly prime, because it can be changed into another prime (21024373) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10512156 + 10512157.

It is an arithmetic number, because the mean of its divisors is an integer number (10512157).

Almost surely, 2^21024313 is an apocalyptic number.

It is an amenable number.

21024313 is a deficient number, since it is larger than the sum of its proper divisors (1).

21024313 is an equidigital number, since it uses as much as digits as its factorization.

21024313 is an odious number, because the sum of its binary digits is odd.

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

The square root of 21024313 is about 4585.2276933649. The cubic root of 21024313 is about 275.9988491515.

Adding to 21024313 its reverse (31342012), we get a palindrome (52366325).

The spelling of 21024313 in words is "twenty-one million, twenty-four thousand, three hundred thirteen".