21243324558 has 16 divisors (see below), whose sum is σ = 43068658896. Its totient is φ = 6984106560.

The previous prime is 21243324551. The next prime is 21243324581. The reversal of 21243324558 is 85542334212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21243324551) 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 7 ways as a sum of consecutive naturals, for example, 24249933 + ... + 24250808.

It is an arithmetic number, because the mean of its divisors is an integer number (2691791181).

Almost surely, 2^21243324558 is an apocalyptic number.

21243324558 is an abundant number, since it is smaller than the sum of its proper divisors (21825334338).

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

21243324558 is a wasteful number, since it uses less digits than its factorization.

21243324558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48500819.

The product of its digits is 230400, while the sum is 39.

The spelling of 21243324558 in words is "twenty-one billion, two hundred forty-three million, three hundred twenty-four thousand, five hundred fifty-eight".