21021102022212 has 144 divisors (see below), whose sum is σ = 55913745363840. Its totient is φ = 6904873963008.

The previous prime is 21021102022183. The next prime is 21021102022243. The reversal of 21021102022212 is 21222020112012.

It is a happy number.

21021102022212 is a `hidden beast` number, since 210 + 21 + 10 + 202 + 221 + 2 = 666.

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

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, 18448489 + ... + 19554767.

It is an arithmetic number, because the mean of its divisors is an integer number (388289898360).

Almost surely, 2^{21021102022212} 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 21021102022212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27956872681920).

21021102022212 is an abundant number, since it is smaller than the sum of its proper divisors (34892643341628).

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

21021102022212 is a wasteful number, since it uses less digits than its factorization.

21021102022212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1106584 (or 1106570 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21021102022212 its reverse (21222020112012), we get a palindrome (42243122134224).

The spelling of 21021102022212 in words is "twenty-one trillion, twenty-one billion, one hundred two million, twenty-two thousand, two hundred twelve".