21212001220202 has 64 divisors (see below), whose sum is σ = 35509627147680. Its totient is φ = 9435906514944.

The previous prime is 21212001220199. The next prime is 21212001220217. The reversal of 21212001220202 is 20202210021212.

It is a happy number.

It can be written as a sum of positive squares in 16 ways, for example, as 16299373561 + 21195701846641 = 127669^2 + 4603879^2 .

It is a super-2 number, since 2×21212001220202² (a number of 27 digits) contains 22 as substring.

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 31 ways as a sum of consecutive naturals, for example, 1097181728 + ... + 1097201060.

Almost surely, 2^{21212001220202} is an apocalyptic number.

21212001220202 is a deficient number, since it is larger than the sum of its proper divisors (14297625927478).

21212001220202 is a wasteful number, since it uses less digits than its factorization.

21212001220202 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21867.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21212001220202 its reverse (20202210021212), we get a palindrome (41414211241414).

The spelling of 21212001220202 in words is "twenty-one trillion, two hundred twelve billion, one million, two hundred twenty thousand, two hundred two".