21001212220122 has 12 divisors (see below), whose sum is σ = 45502626476970. Its totient is φ = 7000404073368.

The previous prime is 21001212220117. The next prime is 21001212220171. The reversal of 21001212220122 is 22102221210012.

It is a happy number.

21001212220122 is a `hidden beast` number, since 210 + 0 + 1 + 212 + 220 + 1 + 22 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20881052237241 + 120159982881 = 4569579^2 + 346641^2 .

It is a Harshad number since it is a multiple of its sum of digits (18), and also a Moran number because the ratio is a prime number: 1166734012229 = 21001212220122 / (2 + 1 + 0 + 0 + 1 + 2 + 1 + 2 + 2 + 2 + 0 + 1 + 2 + 2).

It is a junction number, because it is equal to n+sod(n) for n = 21001212220095 and 21001212220104.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 583367006097 + ... + 583367006132.

Almost surely, 2^{21001212220122} is an apocalyptic number.

21001212220122 is an abundant number, since it is smaller than the sum of its proper divisors (24501414256848).

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

21001212220122 is a wasteful number, since it uses less digits than its factorization.

21001212220122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1166734012237 (or 1166734012234 counting only the distinct ones).

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

Adding to 21001212220122 its reverse (22102221210012), we get a palindrome (43103433430134).

The spelling of 21001212220122 in words is "twenty-one trillion, one billion, two hundred twelve million, two hundred twenty thousand, one hundred twenty-two".