21202401220 has 96 divisors (see below), whose sum is σ = 59781931776. Its totient is φ = 6100185600.

The previous prime is 21202401191. The next prime is 21202401223. The reversal of 21202401220 is 2210420212.

It is a junction number, because it is equal to n+sod(n) for n = 21202401194 and 21202401203.

It is not an unprimeable number, because it can be changed into a prime (21202401223) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 509511 + ... + 549550.

It is an arithmetic number, because the mean of its divisors is an integer number (622728456).

Almost surely, 2^21202401220 is an apocalyptic number.

21202401220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21202401220 is an abundant number, since it is smaller than the sum of its proper divisors (38579530556).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21202401220 is a wasteful number, since it uses less digits than its factorization.

21202401220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1059101 (or 1059099 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21202401220 its reverse (2210420212), we get a palindrome (23412821432).

The spelling of 21202401220 in words is "twenty-one billion, two hundred two million, four hundred one thousand, two hundred twenty".