21435313 has 2 divisors, whose sum is σ = 21435314. Its totient is φ = 21435312.

The previous prime is 21435311. The next prime is 21435319. The reversal of 21435313 is 31353412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16386304 + 5049009 = 4048^2 + 2247^2 .

It is a cyclic number.

It is not a de Polignac number, because 21435313 - 2¹ = 21435311 is a prime.

Together with 21435311, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21435311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10717656 + 10717657.

It is an arithmetic number, because the mean of its divisors is an integer number (10717657).

Almost surely, 2^21435313 is an apocalyptic number.

It is an amenable number.

21435313 is a deficient number, since it is larger than the sum of its proper divisors (1).

21435313 is an equidigital number, since it uses as much as digits as its factorization.

21435313 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1080, while the sum is 22.

The square root of 21435313 is about 4629.8286145386. The cubic root of 21435313 is about 277.7857371171.

Adding to 21435313 its reverse (31353412), we get a palindrome (52788725).

The spelling of 21435313 in words is "twenty-one million, four hundred thirty-five thousand, three hundred thirteen".