21221111322012 has 24 divisors (see below), whose sum is σ = 56589630192256. Its totient is φ = 6063174663408.

The previous prime is 21221111321939. The next prime is 21221111322053. The reversal of 21221111322012 is 21022311112212.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 21221111322012.

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, 126316138738 + ... + 126316138905.

Almost surely, 2^{21221111322012} is an apocalyptic number.

It is an amenable number.

21221111322012 is an abundant number, since it is smaller than the sum of its proper divisors (35368518870244).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21221111322012 is a wasteful number, since it uses less digits than its factorization.

21221111322012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252632277657 (or 252632277655 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 21.

Adding to 21221111322012 its reverse (21022311112212), we get a palindrome (42243422434224).

The spelling of 21221111322012 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred eleven million, three hundred twenty-two thousand, twelve".