21121002216 has 96 divisors (see below), whose sum is σ = 57554640000. Its totient is φ = 6997155840.

The previous prime is 21121002211. The next prime is 21121002233. The reversal of 21121002216 is 61220012112.

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 (21121002211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10564785 + ... + 10566783.

It is an arithmetic number, because the mean of its divisors is an integer number (599527500).

Almost surely, 2^21121002216 is an apocalyptic number.

It is an amenable number.

21121002216 is an abundant number, since it is smaller than the sum of its proper divisors (36433637784).

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

21121002216 is a wasteful number, since it uses less digits than its factorization.

21121002216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2839 (or 2832 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 21121002216 its reverse (61220012112), we get a palindrome (82341014328).

The spelling of 21121002216 in words is "twenty-one billion, one hundred twenty-one million, two thousand, two hundred sixteen".