21243132242 has 16 divisors (see below), whose sum is σ = 32212021464. Its totient is φ = 10506000000.

The previous prime is 21243132241. The next prime is 21243132247. The reversal of 21243132242 is 24223134212.

It can be written as a sum of positive squares in 4 ways, for example, as 18900475441 + 2342656801 = 137479^2 + 48401^2 .

It is not an unprimeable number, because it can be changed into a prime (21243132241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 154742 + ... + 257742.

Almost surely, 2^21243132242 is an apocalyptic number.

21243132242 is a deficient number, since it is larger than the sum of its proper divisors (10968889222).

21243132242 is a wasteful number, since it uses less digits than its factorization.

21243132242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104125.

The product of its digits is 4608, while the sum is 26.

Adding to 21243132242 its reverse (24223134212), we get a palindrome (45466266454).

The spelling of 21243132242 in words is "twenty-one billion, two hundred forty-three million, one hundred thirty-two thousand, two hundred forty-two".