21111221002 has 48 divisors (see below), whose sum is σ = 34386243840. Its totient is φ = 9701866944.

The previous prime is 21111220997. The next prime is 21111221009. The reversal of 21111221002 is 20012211112.

It is not an unprimeable number, because it can be changed into a prime (21111221009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8857903 + ... + 8860285.

It is an arithmetic number, because the mean of its divisors is an integer number (716380080).

Almost surely, 2^21111221002 is an apocalyptic number.

21111221002 is a deficient number, since it is larger than the sum of its proper divisors (13275022838).

21111221002 is a wasteful number, since it uses less digits than its factorization.

21111221002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2695 (or 2666 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21111221002 its reverse (20012211112), we get a palindrome (41123432114).

The spelling of 21111221002 in words is "twenty-one billion, one hundred eleven million, two hundred twenty-one thousand, two".