21001220002 has 32 divisors (see below), whose sum is σ = 36698137344. Its totient is φ = 8826667200.

The previous prime is 21001219997. The next prime is 21001220003. The reversal of 21001220002 is 20002210012.

It is not an unprimeable number, because it can be changed into a prime (21001220003) 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, 2065852 + ... + 2075992.

It is an arithmetic number, because the mean of its divisors is an integer number (1146816792).

Almost surely, 2^21001220002 is an apocalyptic number.

21001220002 is a deficient number, since it is larger than the sum of its proper divisors (15696917342).

21001220002 is a wasteful number, since it uses less digits than its factorization.

21001220002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12994.

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 21001220002 its reverse (20002210012), we get a palindrome (41003430014).

It can be divided in two parts, 210012 and 20002, that multiplied together give a palindrome (4200660024).

The spelling of 21001220002 in words is "twenty-one billion, one million, two hundred twenty thousand, two".