21204502 has 8 divisors (see below), whose sum is σ = 34698312. Its totient is φ = 9638400.

The previous prime is 21204499. The next prime is 21204509. The reversal of 21204502 is 20540212.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21204509) 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 3 ways as a sum of consecutive naturals, for example, 481899 + ... + 481942.

It is an arithmetic number, because the mean of its divisors is an integer number (4337289).

Almost surely, 2^21204502 is an apocalyptic number.

21204502 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21204502 is a deficient number, since it is larger than the sum of its proper divisors (13493810).

21204502 is a wasteful number, since it uses less digits than its factorization.

21204502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 963854.

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 21204502 is about 4604.8346332957. The cubic root of 21204502 is about 276.7850905103.

Adding to 21204502 its reverse (20540212), we get a palindrome (41744714).

The spelling of 21204502 in words is "twenty-one million, two hundred four thousand, five hundred two".