21003011220 has 24 divisors (see below), whose sum is σ = 58808431584. Its totient is φ = 5600802976.

The previous prime is 21003011201. The next prime is 21003011279. The reversal of 21003011220 is 2211030012.

It is a super-2 number, since 2×21003011220² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21003011196 and 21003011205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 175025034 + ... + 175025153.

It is an arithmetic number, because the mean of its divisors is an integer number (2450351316).

Almost surely, 2^21003011220 is an apocalyptic number.

21003011220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21003011220 is an abundant number, since it is smaller than the sum of its proper divisors (37805420364).

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

21003011220 is a wasteful number, since it uses less digits than its factorization.

21003011220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350050199 (or 350050197 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21003011220 its reverse (2211030012), we get a palindrome (23214041232).

The spelling of 21003011220 in words is "twenty-one billion, three million, eleven thousand, two hundred twenty".