21433813 has 8 divisors (see below), whose sum is σ = 22233600. Its totient is φ = 20638128.

The previous prime is 21433771. The next prime is 21433831. The reversal of 21433813 is 31833412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21433813 - 2¹⁷ = 21302741 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21433873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13120 + ... + 14662.

It is an arithmetic number, because the mean of its divisors is an integer number (2779200).

Almost surely, 2^21433813 is an apocalyptic number.

It is an amenable number.

21433813 is a deficient number, since it is larger than the sum of its proper divisors (799787).

21433813 is a wasteful number, since it uses less digits than its factorization.

21433813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2051.

The product of its digits is 1728, while the sum is 25.

The square root of 21433813 is about 4629.6666186671. Note that the first 4 decimals coincide. The cubic root of 21433813 is about 277.7792573373.

The spelling of 21433813 in words is "twenty-one million, four hundred thirty-three thousand, eight hundred thirteen".