21207333 has 8 divisors (see below), whose sum is σ = 32315968. Its totient is φ = 12118464.

The previous prime is 21207331. The next prime is 21207341. The reversal of 21207333 is 33370212.

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

It is not a de Polignac number, because 21207333 - 2¹ = 21207331 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 1009873 = 21207333 / (2 + 1 + 2 + 0 + 7 + 3 + 3 + 3).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21207331) 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 7 ways as a sum of consecutive naturals, for example, 504916 + ... + 504957.

It is an arithmetic number, because the mean of its divisors is an integer number (4039496).

Almost surely, 2^21207333 is an apocalyptic number.

It is an amenable number.

21207333 is a deficient number, since it is larger than the sum of its proper divisors (11108635).

21207333 is a wasteful number, since it uses less digits than its factorization.

21207333 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1009883.

The product of its (nonzero) digits is 756, while the sum is 21.

The square root of 21207333 is about 4605.1420173541. The cubic root of 21207333 is about 276.7974077644.

Adding to 21207333 its reverse (33370212), we get a palindrome (54577545).

It can be divided in two parts, 2120 and 7333, that added together give a triangular number (9453 = T₁₃₇).

The spelling of 21207333 in words is "twenty-one million, two hundred seven thousand, three hundred thirty-three".