21543344530 has 16 divisors (see below), whose sum is σ = 39061073880. Its totient is φ = 8554436992.

The previous prime is 21543344527. The next prime is 21543344531. The reversal of 21543344530 is 3544334512.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 21504169449 + 39175081 = 146643^2 + 6259^2 .

It is not an unprimeable number, because it can be changed into a prime (21543344531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7861165 + ... + 7863904.

Almost surely, 2^21543344530 is an apocalyptic number.

21543344530 is a deficient number, since it is larger than the sum of its proper divisors (17517729350).

21543344530 is a wasteful number, since it uses less digits than its factorization.

21543344530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15725213.

The product of its (nonzero) digits is 86400, while the sum is 34.

The spelling of 21543344530 in words is "twenty-one billion, five hundred forty-three million, three hundred forty-four thousand, five hundred thirty".