21133313 has 4 divisors (see below), whose sum is σ = 21294768. Its totient is φ = 20971860.

The previous prime is 21133309. The next prime is 21133381. The reversal of 21133313 is 31333112.

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 21133313 - 2² = 21133309 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21133291 and 21133300.

It is not an unprimeable number, because it can be changed into a prime (21133303) 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, 80531 + ... + 80792.

It is an arithmetic number, because the mean of its divisors is an integer number (5323692).

Almost surely, 2^21133313 is an apocalyptic number.

It is an amenable number.

21133313 is a deficient number, since it is larger than the sum of its proper divisors (161455).

21133313 is a wasteful number, since it uses less digits than its factorization.

21133313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161454.

The product of its digits is 162, while the sum is 17.

The square root of 21133313 is about 4597.0983239431. The cubic root of 21133313 is about 276.4749968398.

Adding to 21133313 its reverse (31333112), we get a palindrome (52466425).

The spelling of 21133313 in words is "twenty-one million, one hundred thirty-three thousand, three hundred thirteen".