2001221120 has 160 divisors (see below), whose sum is σ = 5015678976. Its totient is φ = 764928000.

The previous prime is 2001221119. The next prime is 2001221141. The reversal of 2001221120 is 211221002.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (160).

It is a super-2 number, since 2×2001221120² = 8009771942268108800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11983277 + ... + 11983443.

Almost surely, 2^2001221120 is an apocalyptic number.

2001221120 is a gapful number since it is divisible by the number (20) 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 2001221120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2507839488).

2001221120 is an abundant number, since it is smaller than the sum of its proper divisors (3014457856).

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

2001221120 is a wasteful number, since it uses less digits than its factorization.

2001221120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 372 (or 356 counting only the distinct ones).

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

The square root of 2001221120 is about 44735.0100033520. The cubic root of 2001221120 is about 1260.1774168582.

Adding to 2001221120 its reverse (211221002), we get a palindrome (2212442122).

The spelling of 2001221120 in words is "two billion, one million, two hundred twenty-one thousand, one hundred twenty".