21324573 has 16 divisors (see below), whose sum is σ = 31838400. Its totient is φ = 14105520.

The previous prime is 21324571. The next prime is 21324619. The reversal of 21324573 is 37542312.

It is not a de Polignac number, because 21324573 - 2¹ = 21324571 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21324571) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 523 + ... + 6551.

It is an arithmetic number, because the mean of its divisors is an integer number (1989900).

Almost surely, 2^21324573 is an apocalyptic number.

It is an amenable number.

21324573 is a deficient number, since it is larger than the sum of its proper divisors (10513827).

21324573 is a wasteful number, since it uses less digits than its factorization.

21324573 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6169 (or 6163 counting only the distinct ones).

The product of its digits is 5040, while the sum is 27.

The square root of 21324573 is about 4617.8537222394. The cubic root of 21324573 is about 277.3065415684.

Adding to 21324573 its reverse (37542312), we get a palindrome (58866885).

The spelling of 21324573 in words is "twenty-one million, three hundred twenty-four thousand, five hundred seventy-three".