21221242102 has 12 divisors (see below), whose sum is σ = 32023698660. Its totient is φ = 10547056676.

The previous prime is 21221242067. The next prime is 21221242109. The reversal of 21221242102 is 20124212212.

It is a super-2 number, since 2×21221242102² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21221242102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221242109) 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 5 ways as a sum of consecutive naturals, for example, 134452 + ... + 246007.

It is an arithmetic number, because the mean of its divisors is an integer number (2668641555).

Almost surely, 2^21221242102 is an apocalyptic number.

21221242102 is a deficient number, since it is larger than the sum of its proper divisors (10802456558).

21221242102 is an equidigital number, since it uses as much as digits as its factorization.

21221242102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380795 (or 380628 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 21221242102 its reverse (20124212212), we get a palindrome (41345454314).

The spelling of 21221242102 in words is "twenty-one billion, two hundred twenty-one million, two hundred forty-two thousand, one hundred two".