21400333 has 4 divisors (see below), whose sum is σ = 21409920. Its totient is φ = 21390748.

The previous prime is 21400277. The next prime is 21400343. The reversal of 21400333 is 33300412.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21400333 - 2¹³ = 21392141 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 (21400343) 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 in 3 ways as a sum of consecutive naturals, for example, 516 + ... + 6562.

It is an arithmetic number, because the mean of its divisors is an integer number (5352480).

Almost surely, 2^21400333 is an apocalyptic number.

It is an amenable number.

21400333 is a deficient number, since it is larger than the sum of its proper divisors (9587).

21400333 is an equidigital number, since it uses as much as digits as its factorization.

21400333 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9586.

The product of its (nonzero) digits is 216, while the sum is 16.

The square root of 21400333 is about 4626.0493944618. The cubic root of 21400333 is about 277.6345499067.

Adding to 21400333 its reverse (33300412), we get a palindrome (54700745).

The spelling of 21400333 in words is "twenty-one million, four hundred thousand, three hundred thirty-three".