2001211220 has 12 divisors (see below), whose sum is σ = 4202543604. Its totient is φ = 800484480.

The previous prime is 2001211181. The next prime is 2001211237. The reversal of 2001211220 is 221121002.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1306677904 + 694533316 = 36148^2 + 26354^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50030261 + ... + 50030300.

It is an arithmetic number, because the mean of its divisors is an integer number (350211967).

Almost surely, 2^2001211220 is an apocalyptic number.

2001211220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2001211220 is an abundant number, since it is smaller than the sum of its proper divisors (2201332384).

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

2001211220 is a wasteful number, since it uses less digits than its factorization.

2001211220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100060570 (or 100060568 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 2001211220 is about 44734.8993516248. The cubic root of 2001211220 is about 1260.1753388308.

Adding to 2001211220 its reverse (221121002), we get a palindrome (2222332222).

The spelling of 2001211220 in words is "two billion, one million, two hundred eleven thousand, two hundred twenty".