21222121202 has 4 divisors (see below), whose sum is σ = 31833181806. Its totient is φ = 10611060600.

The previous prime is 21222121201. The next prime is 21222121211. The reversal of 21222121202 is 20212122212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 21135053641 + 87067561 = 145379^2 + 9331^2 .

It is not an unprimeable number, because it can be changed into a prime (21222121201) 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 as a sum of consecutive naturals, namely, 5305530299 + ... + 5305530302.

Almost surely, 2^21222121202 is an apocalyptic number.

21222121202 is a deficient number, since it is larger than the sum of its proper divisors (10611060604).

21222121202 is a wasteful number, since it uses less digits than its factorization.

21222121202 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10611060603.

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

Adding to 21222121202 its reverse (20212122212), we get a palindrome (41434243414).

The spelling of 21222121202 in words is "twenty-one billion, two hundred twenty-two million, one hundred twenty-one thousand, two hundred two".