21235313 has 4 divisors (see below), whose sum is σ = 23165808. Its totient is φ = 19304820.

The previous prime is 21235297. The next prime is 21235343. The reversal of 21235313 is 31353212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21235313 - 2⁴ = 21235297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21235343) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 965231 + ... + 965252.

It is an arithmetic number, because the mean of its divisors is an integer number (5791452).

Almost surely, 2^21235313 is an apocalyptic number.

It is an amenable number.

21235313 is a deficient number, since it is larger than the sum of its proper divisors (1930495).

21235313 is a wasteful number, since it uses less digits than its factorization.

21235313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1930494.

The product of its digits is 540, while the sum is 20.

The square root of 21235313 is about 4608.1789244777. The cubic root of 21235313 is about 276.9190856124.

Adding to 21235313 its reverse (31353212), we get a palindrome (52588525).

The spelling of 21235313 in words is "twenty-one million, two hundred thirty-five thousand, three hundred thirteen".