21011221232 has 40 divisors (see below), whose sum is σ = 40991459712. Its totient is φ = 10432900800.

The previous prime is 21011221223. The next prime is 21011221291. The reversal of 21011221232 is 23212211012.

It is a self number, because there is not a number n which added to its sum of digits gives 21011221232.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3446507 + ... + 3452597.

Almost surely, 2^21011221232 is an apocalyptic number.

It is an amenable number.

21011221232 is a deficient number, since it is larger than the sum of its proper divisors (19980238480).

21011221232 is a wasteful number, since it uses less digits than its factorization.

21011221232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7557 (or 7551 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21011221232 its reverse (23212211012), we get a palindrome (44223432244).

The spelling of 21011221232 in words is "twenty-one billion, eleven million, two hundred twenty-one thousand, two hundred thirty-two".