21001221001210 has 64 divisors (see below), whose sum is σ = 39671956051200. Its totient is φ = 7989188365312.

The previous prime is 21001221001207. The next prime is 21001221001213. The reversal of 21001221001210 is 1210012210012.

It is an interprime number because it is at equal distance from previous prime (21001221001207) and next prime (21001221001213).

It is not an unprimeable number, because it can be changed into a prime (21001221001213) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 312405522 + ... + 312472738.

It is an arithmetic number, because the mean of its divisors is an integer number (619874313300).

Almost surely, 2^{21001221001210} is an apocalyptic number.

21001221001210 is a deficient number, since it is larger than the sum of its proper divisors (18670735049990).

21001221001210 is a wasteful number, since it uses less digits than its factorization.

21001221001210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75015.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21001221001210 its reverse (1210012210012), we get a palindrome (22211233211222).

The spelling of 21001221001210 in words is "twenty-one trillion, one billion, two hundred twenty-one million, one thousand, two hundred ten".