21043340434 has 8 divisors (see below), whose sum is σ = 32082470028. Its totient is φ = 10349183760.

The previous prime is 21043340429. The next prime is 21043340443. The reversal of 21043340434 is 43404334012.

It can be written as a sum of positive squares in 2 ways, for example, as 18035147025 + 3008193409 = 134295^2 + 54847^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 86243077 + ... + 86243320.

Almost surely, 2^21043340434 is an apocalyptic number.

21043340434 is a deficient number, since it is larger than the sum of its proper divisors (11039129594).

21043340434 is a wasteful number, since it uses less digits than its factorization.

21043340434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172486460.

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

Adding to 21043340434 its reverse (43404334012), we get a palindrome (64447674446).

The spelling of 21043340434 in words is "twenty-one billion, forty-three million, three hundred forty thousand, four hundred thirty-four".