1211001120 has 576 divisors, whose sum is σ = 5162766336. Its totient is φ = 252149760.

The previous prime is 1211001089. The next prime is 1211001139. The reversal of 1211001120 is 211001121.

It is a happy number.

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 an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 6340225 + ... + 6340415.

It is an arithmetic number, because the mean of its divisors is an integer number (8963136).

Almost surely, 2^1211001120 is an apocalyptic number.

1211001120 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 1211001120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2581383168).

1211001120 is an abundant number, since it is smaller than the sum of its proper divisors (3951765216).

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

1211001120 is a wasteful number, since it uses less digits than its factorization.

1211001120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273 (or 262 counting only the distinct ones).

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

The square root of 1211001120 is about 34799.4413748267. The cubic root of 1211001120 is about 1065.8960388697.

Adding to 1211001120 its reverse (211001121), we get a palindrome (1422002241).

Subtracting from 1211001120 its reverse (211001121), we obtain a palindrome (999999999).

It can be divided in two parts, 1211001 and 120, that added together give a palindrome (1211121).

The spelling of 1211001120 in words is "one billion, two hundred eleven million, one thousand, one hundred twenty".