21429811556 has 6 divisors (see below), whose sum is σ = 37502170230. Its totient is φ = 10714905776.

The previous prime is 21429811541. The next prime is 21429811577. The reversal of 21429811556 is 65511892412.

It can be written as a sum of positive squares in only one way, i.e., 20558971456 + 870840100 = 143384^2 + 29510^2 .

It is a super-2 number, since 2×21429811556² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2678726441 + ... + 2678726448.

It is an arithmetic number, because the mean of its divisors is an integer number (6250361705).

Almost surely, 2^21429811556 is an apocalyptic number.

It is an amenable number.

21429811556 is a deficient number, since it is larger than the sum of its proper divisors (16072358674).

21429811556 is a wasteful number, since it uses less digits than its factorization.

21429811556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5357452893 (or 5357452891 counting only the distinct ones).

The product of its digits is 172800, while the sum is 44.

The spelling of 21429811556 in words is "twenty-one billion, four hundred twenty-nine million, eight hundred eleven thousand, five hundred fifty-six".