20001221201010 has 128 divisors (see below), whose sum is σ = 54996128022528. Its totient is φ = 4560408000000.

The previous prime is 20001221201009. The next prime is 20001221201051. The reversal of 20001221201010 is 1010212210002.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 814668235 + ... + 814692785.

It is an arithmetic number, because the mean of its divisors is an integer number (429657250176).

Almost surely, 2^{20001221201010} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20001221201010, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27498064011264).

20001221201010 is an abundant number, since it is smaller than the sum of its proper divisors (34994906821518).

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

20001221201010 is a wasteful number, since it uses less digits than its factorization.

20001221201010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34000.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 20001221201010 its reverse (1010212210002), we get a palindrome (21011433411012).

The spelling of 20001221201010 in words is "twenty trillion, one billion, two hundred twenty-one million, two hundred one thousand, ten".