1211133440 has 160 divisors (see below), whose sum is σ = 3248229600. Its totient is φ = 429260800.

The previous prime is 1211133421. The next prime is 1211133461. The reversal of 1211133440 is 443311121.

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

It is a Harshad number since it is a multiple of its sum of digits (20).

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, 1154036 + ... + 1155084.

It is an arithmetic number, because the mean of its divisors is an integer number (20301435).

Almost surely, 2^1211133440 is an apocalyptic number.

1211133440 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 1211133440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1624114800).

1211133440 is an abundant number, since it is smaller than the sum of its proper divisors (2037096160).

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

1211133440 is a wasteful number, since it uses less digits than its factorization.

1211133440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1124 (or 1108 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 1211133440 is about 34801.3425028403. The cubic root of 1211133440 is about 1065.9348591551.

Adding to 1211133440 its reverse (443311121), we get a palindrome (1654444561).

The spelling of 1211133440 in words is "one billion, two hundred eleven million, one hundred thirty-three thousand, four hundred forty".