21221120021012 has 6 divisors (see below), whose sum is σ = 37136960036778. Its totient is φ = 10610560010504.

The previous prime is 21221120021011. The next prime is 21221120021027. The reversal of 21221120021012 is 21012002112212.

It can be written as a sum of positive squares in only one way, i.e., 13267106899216 + 7954013121796 = 3642404^2 + 2820286^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221120021011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2652640002623 + ... + 2652640002630.

It is an arithmetic number, because the mean of its divisors is an integer number (6189493339463).

Almost surely, 2^{21221120021012} is an apocalyptic number.

It is an amenable number.

21221120021012 is a deficient number, since it is larger than the sum of its proper divisors (15915840015766).

21221120021012 is a wasteful number, since it uses less digits than its factorization.

21221120021012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5305280005257 (or 5305280005255 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21221120021012 its reverse (21012002112212), we get a palindrome (42233122133224).

It can be divided in two parts, 212211200 and 21012, that added together give a palindrome (212232212).

The spelling of 21221120021012 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred twenty million, twenty-one thousand, twelve".