21040340012 has 6 divisors (see below), whose sum is σ = 36820595028. Its totient is φ = 10520170004.

The previous prime is 21040339997. The next prime is 21040340017. The reversal of 21040340012 is 21004304012.

It is not an unprimeable number, because it can be changed into a prime (21040340017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2630042498 + ... + 2630042505.

It is an arithmetic number, because the mean of its divisors is an integer number (6136765838).

Almost surely, 2^21040340012 is an apocalyptic number.

It is an amenable number.

21040340012 is a deficient number, since it is larger than the sum of its proper divisors (15780255016).

21040340012 is a wasteful number, since it uses less digits than its factorization.

21040340012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5260085007 (or 5260085005 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21040340012 its reverse (21004304012), we get a palindrome (42044644024).

The spelling of 21040340012 in words is "twenty-one billion, forty million, three hundred forty thousand, twelve".