21221220202 has 32 divisors (see below), whose sum is σ = 39581563392. Its totient is φ = 8308652544.

The previous prime is 21221220199. The next prime is 21221220203. The reversal of 21221220202 is 20202212212.

It is not an unprimeable number, because it can be changed into a prime (21221220203) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 583378 + ... + 618685.

It is an arithmetic number, because the mean of its divisors is an integer number (1236923856).

Almost surely, 2^21221220202 is an apocalyptic number.

21221220202 is a deficient number, since it is larger than the sum of its proper divisors (18360343190).

21221220202 is a wasteful number, since it uses less digits than its factorization.

21221220202 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1202182.

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21221220202 its reverse (20202212212), we get a palindrome (41423432414).

The spelling of 21221220202 in words is "twenty-one billion, two hundred twenty-one million, two hundred twenty thousand, two hundred two".