21440504234 has 4 divisors (see below), whose sum is σ = 32160756354. Its totient is φ = 10720252116.

The previous prime is 21440504221. The next prime is 21440504237. The reversal of 21440504234 is 43240504412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 12462373225 + 8978131009 = 111635^2 + 94753^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21440504197 and 21440504206.

It is not an unprimeable number, because it can be changed into a prime (21440504237) 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 as a sum of consecutive naturals, namely, 5360126057 + ... + 5360126060.

Almost surely, 2^21440504234 is an apocalyptic number.

21440504234 is a deficient number, since it is larger than the sum of its proper divisors (10720252120).

21440504234 is a wasteful number, since it uses less digits than its factorization.

21440504234 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10720252119.

The product of its (nonzero) digits is 15360, while the sum is 29.

The spelling of 21440504234 in words is "twenty-one billion, four hundred forty million, five hundred four thousand, two hundred thirty-four".