1001221120 has 88 divisors (see below), whose sum is σ = 2543258304. Its totient is φ = 376897536.

The previous prime is 1001221097. The next prime is 1001221127. The reversal of 1001221120 is 211221001.

It is a super-2 number, since 2×1001221120² = 2004887462268108800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 1001221097 and 1001221106.

It is not an unprimeable number, because it can be changed into a prime (1001221127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81289 + ... + 92791.

Almost surely, 2^1001221120 is an apocalyptic number.

1001221120 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 1001221120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1271629152).

1001221120 is an abundant number, since it is smaller than the sum of its proper divisors (1542037184).

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

1001221120 is a wasteful number, since it uses less digits than its factorization.

1001221120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11545 (or 11527 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 1001221120 is about 31642.0783135369. The cubic root of 1001221120 is about 1000.4068744307.

Adding to 1001221120 its reverse (211221001), we get a palindrome (1212442121).

The spelling of 1001221120 in words is "one billion, one million, two hundred twenty-one thousand, one hundred twenty".