1321351561440 has 240 divisors, whose sum is σ = 4771720034928. Its totient is φ = 344165842944.

The previous prime is 1321351561403. The next prime is 1321351561459. The reversal of 1321351561440 is 441651531231.

1321351561440 is a `hidden beast` number, since 1 + 3 + 2 + 1 + 3 + 51 + 561 + 4 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1321351561395 and 1321351561404.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 628257 + ... + 1742816.

Almost surely, 2^{1321351561440} is an apocalyptic number.

1321351561440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1321351561440 is an abundant number, since it is smaller than the sum of its proper divisors (3450368473488).

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

1321351561440 is a wasteful number, since it uses less digits than its factorization.

1321351561440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2371143 (or 2371126 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The spelling of 1321351561440 in words is "one trillion, three hundred twenty-one billion, three hundred fifty-one million, five hundred sixty-one thousand, four hundred forty".