21543052340 has 24 divisors (see below), whose sum is σ = 47621484960. Its totient is φ = 8163682848.

The previous prime is 21543052339. The next prime is 21543052351. The reversal of 21543052340 is 4325034512.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28345742 + ... + 28346501.

It is an arithmetic number, because the mean of its divisors is an integer number (1984228540).

Almost surely, 2^21543052340 is an apocalyptic number.

21543052340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21543052340 is an abundant number, since it is smaller than the sum of its proper divisors (26078432620).

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

21543052340 is a wasteful number, since it uses less digits than its factorization.

21543052340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56692271 (or 56692269 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 29.

Adding to 21543052340 its reverse (4325034512), we get a palindrome (25868086852).

The spelling of 21543052340 in words is "twenty-one billion, five hundred forty-three million, fifty-two thousand, three hundred forty".