21204573 has 8 divisors (see below), whose sum is σ = 30447648. Its totient is φ = 13048944.

The previous prime is 21204571. The next prime is 21204583. The reversal of 21204573 is 37540212.

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

It is not a de Polignac number, because 21204573 - 2¹ = 21204571 is a prime.

It is a super-2 number, since 2×21204573² = 899267832224658, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21204571) 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, 271815 + ... + 271892.

It is an arithmetic number, because the mean of its divisors is an integer number (3805956).

Almost surely, 2^21204573 is an apocalyptic number.

It is an amenable number.

21204573 is a deficient number, since it is larger than the sum of its proper divisors (9243075).

21204573 is a wasteful number, since it uses less digits than its factorization.

21204573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 543723.

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 21204573 is about 4604.8423425781. The cubic root of 21204573 is about 276.7853994340.

Adding to 21204573 its reverse (37540212), we get a palindrome (58744785).

The spelling of 21204573 in words is "twenty-one million, two hundred four thousand, five hundred seventy-three".