21213313552 has 20 divisors (see below), whose sum is σ = 41112791356. Its totient is φ = 10603560960.

The previous prime is 21213313549. The next prime is 21213313573. The reversal of 21213313552 is 25531331212.

It can be written as a sum of positive squares in 2 ways, for example, as 717382656 + 20495930896 = 26784^2 + 143164^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21213313552.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136449 + ... + 247072.

Almost surely, 2^21213313552 is an apocalyptic number.

It is an amenable number.

21213313552 is a deficient number, since it is larger than the sum of its proper divisors (19899477804).

21213313552 is a wasteful number, since it uses less digits than its factorization.

21213313552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386986 (or 386980 counting only the distinct ones).

The product of its digits is 5400, while the sum is 28.

Adding to 21213313552 its reverse (25531331212), we get a palindrome (46744644764).

The spelling of 21213313552 in words is "twenty-one billion, two hundred thirteen million, three hundred thirteen thousand, five hundred fifty-two".