21001132220 has 12 divisors (see below), whose sum is σ = 44102377704. Its totient is φ = 8400452880.

The previous prime is 21001132213. The next prime is 21001132241. The reversal of 21001132220 is 2223110012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21001132195 and 21001132204.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 525028286 + ... + 525028325.

It is an arithmetic number, because the mean of its divisors is an integer number (3675198142).

Almost surely, 2^21001132220 is an apocalyptic number.

21001132220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001132220 is an abundant number, since it is smaller than the sum of its proper divisors (23101245484).

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

21001132220 is a wasteful number, since it uses less digits than its factorization.

21001132220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1050056620 (or 1050056618 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21001132220 its reverse (2223110012), we get a palindrome (23224242232).

The spelling of 21001132220 in words is "twenty-one billion, one million, one hundred thirty-two thousand, two hundred twenty".