1211323311440 has 160 divisors (see below), whose sum is σ = 3180575894400. Its totient is φ = 424987637760.

The previous prime is 1211323311437. The next prime is 1211323311479. The reversal of 1211323311440 is 441133231121.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 37217414 + ... + 37249946.

It is an arithmetic number, because the mean of its divisors is an integer number (19878599340).

Almost surely, 2^{1211323311440} is an apocalyptic number.

1211323311440 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 1211323311440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1590287947200).

1211323311440 is an abundant number, since it is smaller than the sum of its proper divisors (1969252582960).

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

1211323311440 is a wasteful number, since it uses less digits than its factorization.

1211323311440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34045 (or 34039 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

Adding to 1211323311440 its reverse (441133231121), we get a palindrome (1652456542561).

The spelling of 1211323311440 in words is "one trillion, two hundred eleven billion, three hundred twenty-three million, three hundred eleven thousand, four hundred forty".