21003332220 has 72 divisors (see below), whose sum is σ = 68610892896. Its totient is φ = 5170050432.

The previous prime is 21003332219. The next prime is 21003332221. The reversal of 21003332220 is 2223330012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21003332219) and next prime (21003332221).

It is a super-2 number, since 2×21003332220² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21003332193 and 21003332202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21003332221) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4485552 + ... + 4490231.

It is an arithmetic number, because the mean of its divisors is an integer number (952929068).

Almost surely, 2^21003332220 is an apocalyptic number.

21003332220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21003332220 is an abundant number, since it is smaller than the sum of its proper divisors (47607560676).

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

21003332220 is a wasteful number, since it uses less digits than its factorization.

21003332220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8975811 (or 8975806 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 18.

Adding to 21003332220 its reverse (2223330012), we get a palindrome (23226662232).

The spelling of 21003332220 in words is "twenty-one billion, three million, three hundred thirty-two thousand, two hundred twenty".