20001221211210 has 16 divisors (see below), whose sum is σ = 48002930906976. Its totient is φ = 5333658989648.

The previous prime is 20001221211187. The next prime is 20001221211227. The reversal of 20001221211210 is 1211212210002.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20001221211210.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 333353686824 + ... + 333353686883.

It is an arithmetic number, because the mean of its divisors is an integer number (3000183181686).

Almost surely, 2^{20001221211210} is an apocalyptic number.

20001221211210 is an abundant number, since it is smaller than the sum of its proper divisors (28001709695766).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20001221211210 is a wasteful number, since it uses less digits than its factorization.

20001221211210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 666707373717.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 20001221211210 its reverse (1211212210002), we get a palindrome (21212433421212).

The spelling of 20001221211210 in words is "twenty trillion, one billion, two hundred twenty-one million, two hundred eleven thousand, two hundred ten".