21011002222122 has 160 divisors (see below), whose sum is σ = 52660067328000. Its totient is φ = 6206427269280.

The previous prime is 21011002222081. The next prime is 21011002222127. The reversal of 21011002222122 is 22122220011012.

It is a happy number.

21011002222122 is a `hidden beast` number, since 210 + 110 + 0 + 2 + 222 + 122 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 21011002222095 and 21011002222104.

It is not an unprimeable number, because it can be changed into a prime (21011002222127) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 37961623 + ... + 38511125.

It is an arithmetic number, because the mean of its divisors is an integer number (329125420800).

Almost surely, 2^{21011002222122} is an apocalyptic number.

21011002222122 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21011002222122, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26330033664000).

21011002222122 is an abundant number, since it is smaller than the sum of its proper divisors (31649065105878).

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

21011002222122 is a wasteful number, since it uses less digits than its factorization.

21011002222122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 550070 (or 550061 counting only the distinct ones).

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

Adding to 21011002222122 its reverse (22122220011012), we get a palindrome (43133222233134).

The spelling of 21011002222122 in words is "twenty-one trillion, eleven billion, two million, two hundred twenty-two thousand, one hundred twenty-two".