21243300340 has 12 divisors (see below), whose sum is σ = 44610930756. Its totient is φ = 8497320128.

The previous prime is 21243300293. The next prime is 21243300349. The reversal of 21243300340 is 4300334212.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 7521052176 + 13722248164 = 86724^2 + 117142^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21243300349) 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 3 ways as a sum of consecutive naturals, for example, 531082489 + ... + 531082528.

It is an arithmetic number, because the mean of its divisors is an integer number (3717577563).

Almost surely, 2^21243300340 is an apocalyptic number.

21243300340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21243300340 is an abundant number, since it is smaller than the sum of its proper divisors (23367630416).

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

21243300340 is a wasteful number, since it uses less digits than its factorization.

21243300340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1062165026 (or 1062165024 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 22.

Adding to 21243300340 its reverse (4300334212), we get a palindrome (25543634552).

The spelling of 21243300340 in words is "twenty-one billion, two hundred forty-three million, three hundred thousand, three hundred forty".