21043351052 has 12 divisors (see below), whose sum is σ = 36972582696. Its totient is φ = 10479756000.

The previous prime is 21043351039. The next prime is 21043351057. The reversal of 21043351052 is 25015334012.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21043351057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10478753 + ... + 10480760.

It is an arithmetic number, because the mean of its divisors is an integer number (3081048558).

Almost surely, 2^21043351052 is an apocalyptic number.

It is an amenable number.

21043351052 is a deficient number, since it is larger than the sum of its proper divisors (15929231644).

21043351052 is a wasteful number, since it uses less digits than its factorization.

21043351052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20959768 (or 20959766 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 26.

Adding to 21043351052 its reverse (25015334012), we get a palindrome (46058685064).

The spelling of 21043351052 in words is "twenty-one billion, forty-three million, three hundred fifty-one thousand, fifty-two".