21216657550052 has 6 divisors (see below), whose sum is σ = 37129150712598. Its totient is φ = 10608328775024.

The previous prime is 21216657549991. The next prime is 21216657550111. The reversal of 21216657550052 is 25005575661212.

It can be written as a sum of positive squares in only one way, i.e., 20045552655076 + 1171104894976 = 4477226^2 + 1082176^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21216657549979 and 21216657550006.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2652082193753 + ... + 2652082193760.

It is an arithmetic number, because the mean of its divisors is an integer number (6188191785433).

Almost surely, 2^{21216657550052} is an apocalyptic number.

It is an amenable number.

21216657550052 is a deficient number, since it is larger than the sum of its proper divisors (15912493162546).

21216657550052 is a wasteful number, since it uses less digits than its factorization.

21216657550052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5304164387517 (or 5304164387515 counting only the distinct ones).

The product of its (nonzero) digits is 1260000, while the sum is 47.

The spelling of 21216657550052 in words is "twenty-one trillion, two hundred sixteen billion, six hundred fifty-seven million, five hundred fifty thousand, fifty-two".