21021221001012 has 12 divisors (see below), whose sum is σ = 49049515669056. Its totient is φ = 7007073667000.

The previous prime is 21021221000947. The next prime is 21021221001047. The reversal of 21021221001012 is 21010012212012.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 21021221000982 and 21021221001000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 875884208364 + ... + 875884208387.

It is an arithmetic number, because the mean of its divisors is an integer number (4087459639088).

Almost surely, 2^{21021221001012} is an apocalyptic number.

It is an amenable number.

21021221001012 is an abundant number, since it is smaller than the sum of its proper divisors (28028294668044).

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

21021221001012 is a wasteful number, since it uses less digits than its factorization.

21021221001012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1751768416758 (or 1751768416756 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21021221001012 its reverse (21010012212012), we get a palindrome (42031233213024).

The spelling of 21021221001012 in words is "twenty-one trillion, twenty-one billion, two hundred twenty-one million, one thousand, twelve".