21338573 has 8 divisors (see below), whose sum is σ = 22079736. Its totient is φ = 20608000.

The previous prime is 21338563. The next prime is 21338579. The reversal of 21338573 is 37583312.

It can be written as a sum of positive squares in 4 ways, for example, as 4380649 + 16957924 = 2093^2 + 4118^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21338573 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21338579) 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, 1565 + ... + 6717.

It is an arithmetic number, because the mean of its divisors is an integer number (2759967).

Almost surely, 2^21338573 is an apocalyptic number.

It is an amenable number.

21338573 is a deficient number, since it is larger than the sum of its proper divisors (741163).

21338573 is a wasteful number, since it uses less digits than its factorization.

21338573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5295.

The product of its digits is 15120, while the sum is 32.

The square root of 21338573 is about 4619.3693292483. The cubic root of 21338573 is about 277.3672140188.

The spelling of 21338573 in words is "twenty-one million, three hundred thirty-eight thousand, five hundred seventy-three".