21212403332 has 6 divisors (see below), whose sum is σ = 37121705838. Its totient is φ = 10606201664.

The previous prime is 21212403323. The next prime is 21212403343. The reversal of 21212403332 is 23330421212.

It can be written as a sum of positive squares in only one way, i.e., 19741374016 + 1471029316 = 140504^2 + 38354^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21212403298 and 21212403307.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2651550413 + ... + 2651550420.

It is an arithmetic number, because the mean of its divisors is an integer number (6186950973).

Almost surely, 2^21212403332 is an apocalyptic number.

It is an amenable number.

21212403332 is a deficient number, since it is larger than the sum of its proper divisors (15909302506).

21212403332 is a wasteful number, since it uses less digits than its factorization.

21212403332 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5303100837 (or 5303100835 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 23.

Adding to 21212403332 its reverse (23330421212), we get a palindrome (44542824544).

The spelling of 21212403332 in words is "twenty-one billion, two hundred twelve million, four hundred three thousand, three hundred thirty-two".