21221221012012 has 48 divisors (see below), whose sum is σ = 43203591889920. Its totient is φ = 8932003938432.

The previous prime is 21221221011941. The next prime is 21221221012087. The reversal of 21221221012012 is 21021012212212.

It is a super-2 number, since 2×21221221012012² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4511188 + ... + 7924219.

It is an arithmetic number, because the mean of its divisors is an integer number (900074831040).

Almost surely, 2^{21221221012012} is an apocalyptic number.

It is an amenable number.

21221221012012 is an abundant number, since it is smaller than the sum of its proper divisors (21982370877908).

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

21221221012012 is a wasteful number, since it uses less digits than its factorization.

21221221012012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12436510 (or 12436508 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21221221012012 its reverse (21021012212212), we get a palindrome (42242233224224).

The spelling of 21221221012012 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred twenty-one million, twelve thousand, twelve".