1221010213220 has 96 divisors (see below), whose sum is σ = 3002640748800. Its totient is φ = 416894446080.

The previous prime is 1221010213201. The next prime is 1221010213261. The reversal of 1221010213220 is 223120101221.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1283987 + ... + 2022533.

It is an arithmetic number, because the mean of its divisors is an integer number (31277507800).

Almost surely, 2^{1221010213220} is an apocalyptic number.

1221010213220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221010213220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1501320374400).

1221010213220 is an abundant number, since it is smaller than the sum of its proper divisors (1781630535580).

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

1221010213220 is a wasteful number, since it uses less digits than its factorization.

1221010213220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 738818 (or 738802 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 1221010213220 its reverse (223120101221), we get a palindrome (1444130314441).

The spelling of 1221010213220 in words is "one trillion, two hundred twenty-one billion, ten million, two hundred thirteen thousand, two hundred twenty".