21213566163652 has 72 divisors (see below), whose sum is σ = 40937152674600. Its totient is φ = 9579703910400.

The previous prime is 21213566163623. The next prime is 21213566163653. The reversal of 21213566163652 is 25636166531212.

It can be written as a sum of positive squares in 12 ways, for example, as 20226372895876 + 987193267776 = 4497374^2 + 993576^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21213566163596 and 21213566163605.

It is not an unprimeable number, because it can be changed into a prime (21213566163653) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9351724 + ... + 11396572.

It is an arithmetic number, because the mean of its divisors is an integer number (568571564925).

Almost surely, 2^{21213566163652} is an apocalyptic number.

It is an amenable number.

21213566163652 is a deficient number, since it is larger than the sum of its proper divisors (19723586510948).

21213566163652 is a wasteful number, since it uses less digits than its factorization.

21213566163652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2045033 (or 2044970 counting only the distinct ones).

The product of its digits is 2332800, while the sum is 49.

The spelling of 21213566163652 in words is "twenty-one trillion, two hundred thirteen billion, five hundred sixty-six million, one hundred sixty-three thousand, six hundred fifty-two".