1321220131440 has 640 divisors, whose sum is σ = 4699975753728. Its totient is φ = 306662400000.

The previous prime is 1321220131421. The next prime is 1321220131463. The reversal of 1321220131440 is 441310221231.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 1321220131440.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1000165980 + ... + 1000167300.

Almost surely, 2^{1321220131440} is an apocalyptic number.

1321220131440 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 1321220131440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2349987876864).

1321220131440 is an abundant number, since it is smaller than the sum of its proper divisors (3378755622288).

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

1321220131440 is a wasteful number, since it uses less digits than its factorization.

1321220131440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1502 (or 1474 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

Adding to 1321220131440 its reverse (441310221231), we get a palindrome (1762530352671).

It can be divided in two parts, 1321220 and 131440, that added together give a triangular number (1452660 = T₁₇₀₄).

The spelling of 1321220131440 in words is "one trillion, three hundred twenty-one billion, two hundred twenty million, one hundred thirty-one thousand, four hundred forty".