1001211120 has 720 divisors, whose sum is σ = 4399405920. Its totient is φ = 202051584.

The previous prime is 1001211089. The next prime is 1001211121. The reversal of 1001211120 is 211121001.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001211121) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 16969651 + ... + 16969709.

It is an arithmetic number, because the mean of its divisors is an integer number (6110286).

Almost surely, 2^1001211120 is an apocalyptic number.

1001211120 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 1001211120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2199702960).

1001211120 is an abundant number, since it is smaller than the sum of its proper divisors (3398194800).

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

1001211120 is a wasteful number, since it uses less digits than its factorization.

1001211120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142 (or 126 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 1001211120 is about 31641.9202957090. The cubic root of 1001211120 is about 1000.4035437972.

Adding to 1001211120 its reverse (211121001), we get a palindrome (1212332121).

The spelling of 1001211120 in words is "one billion, one million, two hundred eleven thousand, one hundred twenty".