21001022221210 has 24 divisors (see below), whose sum is σ = 38139330226140. Its totient is φ = 8326068936192.

The previous prime is 21001022221159. The next prime is 21001022221271. The reversal of 21001022221210 is 1212222010012.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 3025821981121 + 17975200240089 = 1739489^2 + 4239717^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 82106715 + ... + 82362094.

Almost surely, 2^{21001022221210} is an apocalyptic number.

21001022221210 is a deficient number, since it is larger than the sum of its proper divisors (17138308004930).

21001022221210 is a wasteful number, since it uses less digits than its factorization.

21001022221210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164469042 (or 164468929 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21001022221210 its reverse (1212222010012), we get a palindrome (22213244231222).

The spelling of 21001022221210 in words is "twenty-one trillion, one billion, twenty-two million, two hundred twenty-one thousand, two hundred ten".