21204220502 has 16 divisors (see below), whose sum is σ = 32265391200. Its totient is φ = 10449300672.

The previous prime is 21204220463. The next prime is 21204220507. The reversal of 21204220502 is 20502240212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21204220507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 152348 + ... + 256160.

It is an arithmetic number, because the mean of its divisors is an integer number (2016586950).

Almost surely, 2^21204220502 is an apocalyptic number.

21204220502 is a deficient number, since it is larger than the sum of its proper divisors (11061170698).

21204220502 is a wasteful number, since it uses less digits than its factorization.

21204220502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105287.

The product of its (nonzero) digits is 640, while the sum is 20.

Adding to 21204220502 its reverse (20502240212), we get a palindrome (41706460714).

The spelling of 21204220502 in words is "twenty-one billion, two hundred four million, two hundred twenty thousand, five hundred two".