21321411220 has 48 divisors (see below), whose sum is σ = 48565128528. Its totient is φ = 7831101440.

The previous prime is 21321411197. The next prime is 21321411227. The reversal of 21321411220 is 2211412312.

It can be written as a sum of positive squares in 8 ways, for example, as 6700732164 + 14620679056 = 81858^2 + 120916^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21321411227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 750817 + ... + 778696.

It is an arithmetic number, because the mean of its divisors is an integer number (1011773511).

Almost surely, 2^21321411220 is an apocalyptic number.

21321411220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21321411220 is an abundant number, since it is smaller than the sum of its proper divisors (27243717308).

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

21321411220 is a wasteful number, since it uses less digits than its factorization.

21321411220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1529580 (or 1529578 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 21321411220 its reverse (2211412312), we get a palindrome (23532823532).

The spelling of 21321411220 in words is "twenty-one billion, three hundred twenty-one million, four hundred eleven thousand, two hundred twenty".