21043402312 has 16 divisors (see below), whose sum is σ = 39721189500. Its totient is φ = 10451085120.

The previous prime is 21043402283. The next prime is 21043402339. The reversal of 21043402312 is 21320434012.

It can be written as a sum of positive squares in 2 ways, for example, as 20986157956 + 57244356 = 144866^2 + 7566^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8825739 + ... + 8828122.

Almost surely, 2^21043402312 is an apocalyptic number.

It is an amenable number.

21043402312 is a deficient number, since it is larger than the sum of its proper divisors (18677787188).

21043402312 is a wasteful number, since it uses less digits than its factorization.

21043402312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17654016 (or 17654012 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

Adding to 21043402312 its reverse (21320434012), we get a palindrome (42363836324).

The spelling of 21043402312 in words is "twenty-one billion, forty-three million, four hundred two thousand, three hundred twelve".