21221212220010 has 96 divisors (see below), whose sum is σ = 62808077973888. Its totient is φ = 4920860799360.

The previous prime is 21221212219997. The next prime is 21221212220017. The reversal of 21221212220010 is 1002221212212.

It is a happy number.

21221212220010 is a `hidden beast` number, since 2 + 1 + 221 + 212 + 220 + 0 + 10 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (21221212220017) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 465967837 + ... + 466013376.

It is an arithmetic number, because the mean of its divisors is an integer number (654250812228).

Almost surely, 2^{21221212220010} is an apocalyptic number.

21221212220010 is an abundant number, since it is smaller than the sum of its proper divisors (41586865753878).

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

21221212220010 is a wasteful number, since it uses less digits than its factorization.

21221212220010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 931981260 (or 931981257 counting only the distinct ones).

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

Adding to 21221212220010 its reverse (1002221212212), we get a palindrome (22223433432222).

The spelling of 21221212220010 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred twelve million, two hundred twenty thousand, ten".