21220211121012 has 144 divisors (see below), whose sum is σ = 55742173014528. Its totient is φ = 6801600294720.

The previous prime is 21220211120957. The next prime is 21220211121029. The reversal of 21220211121012 is 21012111202212.

21220211121012 is a `hidden beast` number, since 21 + 220 + 211 + 1 + 210 + 1 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 74925823 + ... + 75208505.

It is an arithmetic number, because the mean of its divisors is an integer number (387098423712).

Almost surely, 2^{21220211121012} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21220211121012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27871086507264).

21220211121012 is an abundant number, since it is smaller than the sum of its proper divisors (34521961893516).

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

21220211121012 is a wasteful number, since it uses less digits than its factorization.

21220211121012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283490 (or 283485 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21220211121012 its reverse (21012111202212), we get a palindrome (42232322323224).

The spelling of 21220211121012 in words is "twenty-one trillion, two hundred twenty billion, two hundred eleven million, one hundred twenty-one thousand, twelve".