21333819 has 8 divisors (see below), whose sum is σ = 30633232. Its totient is φ = 13128480.

The previous prime is 21333779. The next prime is 21333839. The reversal of 21333819 is 91833312.

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

It is not a de Polignac number, because 21333819 - 2¹⁷ = 21202747 is a prime.

It is a super-2 number, since 2×21333819² = 910263666249522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21333839) 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, 273472 + ... + 273549.

It is an arithmetic number, because the mean of its divisors is an integer number (3829154).

Almost surely, 2^21333819 is an apocalyptic number.

21333819 is a deficient number, since it is larger than the sum of its proper divisors (9299413).

21333819 is a wasteful number, since it uses less digits than its factorization.

21333819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 547037.

The product of its digits is 3888, while the sum is 30.

The square root of 21333819 is about 4618.8547281767. The cubic root of 21333819 is about 277.3466143647.

The spelling of 21333819 in words is "twenty-one million, three hundred thirty-three thousand, eight hundred nineteen".