2001222144 has 60 divisors (see below), whose sum is σ = 5775675906. Its totient is φ = 667072512.

The previous prime is 2001222131. The next prime is 2001222149. The reversal of 2001222144 is 4412221002.

It can be written as a sum of positive squares in only one way, i.e., 1945868544 + 55353600 = 44112^2 + 7440^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (2001222149) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 212539 + ... + 221754.

Almost surely, 2^2001222144 is an apocalyptic number.

2001222144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

2001222144 is an abundant number, since it is smaller than the sum of its proper divisors (3774453762).

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

2001222144 is an equidigital number, since it uses as much as digits as its factorization.

2001222144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 434317 (or 434298 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 2001222144 is about 44735.0214485251. The cubic root of 2001222144 is about 1260.1776317972.

Adding to 2001222144 its reverse (4412221002), we get a palindrome (6413443146).

The spelling of 2001222144 in words is "two billion, one million, two hundred twenty-two thousand, one hundred forty-four".