21243442330 has 64 divisors (see below), whose sum is σ = 42881021568. Its totient is φ = 7509231360.

The previous prime is 21243442303. The next prime is 21243442331. The reversal of 21243442330 is 3324434212.

It is not an unprimeable number, because it can be changed into a prime (21243442331) 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 31 ways as a sum of consecutive naturals, for example, 6888969 + ... + 6892051.

It is an arithmetic number, because the mean of its divisors is an integer number (670015962).

Almost surely, 2^21243442330 is an apocalyptic number.

21243442330 is an abundant number, since it is smaller than the sum of its proper divisors (21637579238).

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

21243442330 is a wasteful number, since it uses less digits than its factorization.

21243442330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4831.

The product of its (nonzero) digits is 13824, while the sum is 28.

Adding to 21243442330 its reverse (3324434212), we get a palindrome (24567876542).

The spelling of 21243442330 in words is "twenty-one billion, two hundred forty-three million, four hundred forty-two thousand, three hundred thirty".