21343121300 has 72 divisors (see below), whose sum is σ = 48049659000. Its totient is φ = 8219115520.

The previous prime is 21343121243. The next prime is 21343121309. The reversal of 21343121300 is 312134312.

It can be written as a sum of positive squares in 12 ways, for example, as 2058799876 + 19284321424 = 45374^2 + 138868^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21343121309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1013276 + ... + 1034124.

It is an arithmetic number, because the mean of its divisors is an integer number (667356375).

Almost surely, 2^21343121300 is an apocalyptic number.

21343121300 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21343121300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24024829500).

21343121300 is an abundant number, since it is smaller than the sum of its proper divisors (26706537700).

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

21343121300 is a wasteful number, since it uses less digits than its factorization.

21343121300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21245 (or 21238 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 21343121300 its reverse (312134312), we get a palindrome (21655255612).

The spelling of 21343121300 in words is "twenty-one billion, three hundred forty-three million, one hundred twenty-one thousand, three hundred".