21234200442 has 64 divisors (see below), whose sum is σ = 52285981440. Its totient is φ = 5598388224.

The previous prime is 21234200441. The next prime is 21234200473. The reversal of 21234200442 is 24400243212.

It is a super-2 number, since 2×21234200442² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21234200441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2722284 + ... + 2730072.

It is an arithmetic number, because the mean of its divisors is an integer number (816968460).

Almost surely, 2^21234200442 is an apocalyptic number.

21234200442 is an abundant number, since it is smaller than the sum of its proper divisors (31051780998).

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

21234200442 is a wasteful number, since it uses less digits than its factorization.

21234200442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12807.

The product of its (nonzero) digits is 3072, while the sum is 24.

Adding to 21234200442 its reverse (24400243212), we get a palindrome (45634443654).

The spelling of 21234200442 in words is "twenty-one billion, two hundred thirty-four million, two hundred thousand, four hundred forty-two".