21221032312 has 8 divisors (see below), whose sum is σ = 39789435600. Its totient is φ = 10610516152.

The previous prime is 21221032279. The next prime is 21221032321. The reversal of 21221032312 is 21323012212.

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 21221032312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1326314512 + ... + 1326314527.

It is an arithmetic number, because the mean of its divisors is an integer number (4973679450).

Almost surely, 2^21221032312 is an apocalyptic number.

It is an amenable number.

21221032312 is a deficient number, since it is larger than the sum of its proper divisors (18568403288).

21221032312 is a wasteful number, since it uses less digits than its factorization.

21221032312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2652629045 (or 2652629041 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21221032312 its reverse (21323012212), we get a palindrome (42544044524).

The spelling of 21221032312 in words is "twenty-one billion, two hundred twenty-one million, thirty-two thousand, three hundred twelve".