21121221001012 has 48 divisors (see below), whose sum is σ = 41307389444160. Its totient is φ = 9366035270400.

The previous prime is 21121221000961. The next prime is 21121221001033. The reversal of 21121221001012 is 21010012212112.

It is a super-2 number, since 2×21121221001012² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49830118 + ... + 50252194.

It is an arithmetic number, because the mean of its divisors is an integer number (860570613420).

Almost surely, 2^{21121221001012} is an apocalyptic number.

21121221001012 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21121221001012 is a deficient number, since it is larger than the sum of its proper divisors (20186168443148).

21121221001012 is a wasteful number, since it uses less digits than its factorization.

21121221001012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 449872 (or 449870 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21121221001012 its reverse (21010012212112), we get a palindrome (42131233213124).

The spelling of 21121221001012 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred twenty-one million, one thousand, twelve".