21043355412 has 24 divisors (see below), whose sum is σ = 51989466816. Its totient is φ = 6601836928.

The previous prime is 21043355393. The next prime is 21043355423. The reversal of 21043355412 is 21455334012.

It is a self number, because there is not a number n which added to its sum of digits gives 21043355412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51576648 + ... + 51577055.

It is an arithmetic number, because the mean of its divisors is an integer number (2166227784).

Almost surely, 2^21043355412 is an apocalyptic number.

It is an amenable number.

21043355412 is an abundant number, since it is smaller than the sum of its proper divisors (30946111404).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21043355412 is a wasteful number, since it uses less digits than its factorization.

21043355412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103153727 (or 103153725 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 30.

Adding to 21043355412 its reverse (21455334012), we get a palindrome (42498689424).

The spelling of 21043355412 in words is "twenty-one billion, forty-three million, three hundred fifty-five thousand, four hundred twelve".