20121221210 has 16 divisors (see below), whose sum is σ = 36220972392.
Its totient is φ = 8047872000.
The previous prime is 20121221161. The next prime is 20121221249. The reversal of 20121221210 is 1212212102.
It can be written as a sum of positive squares in 4 ways, for example, as 19979539801 + 141681409 = 141349^2 + 11903^2
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, 74150 + ... + 213870.
Almost surely, 220121221210 is an apocalyptic number.
20121221210 is a deficient number, since it is larger than the sum of its proper divisors (16099751182).
20121221210 is a wasteful number, since it uses less digits than its factorization.
20121221210 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 154129.
The product of its (nonzero) digits is 32, while the sum is 14.
Adding to 20121221210 its reverse (1212212102), we get a palindrome (21333433312).
The spelling of 20121221210 in words is "twenty billion, one hundred twenty-one million, two hundred twenty-one thousand, two hundred ten".