1321305840 has 240 divisors, whose sum is σ = 4698038592. Its totient is φ = 332107776.

The previous prime is 1321305833. The next prime is 1321305907. The reversal of 1321305840 is 485031231.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1208334 + ... + 1209426.

Almost surely, 2^1321305840 is an apocalyptic number.

1321305840 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 1321305840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2349019296).

1321305840 is an abundant number, since it is smaller than the sum of its proper divisors (3376732752).

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

1321305840 is a wasteful number, since it uses less digits than its factorization.

1321305840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1208 (or 1199 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 1321305840 is about 36349.7708383423. The cubic root of 1321305840 is about 1097.3229225708.

The spelling of 1321305840 in words is "one billion, three hundred twenty-one million, three hundred five thousand, eight hundred forty".