1305987840 has 576 divisors, whose sum is σ = 5086126080. Its totient is φ = 316293120.

The previous prime is 1305987829. The next prime is 1305987841. The reversal of 1305987840 is 487895031.

1305987840 is a `hidden beast` number, since 13 + 0 + 598 + 7 + 8 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (1305987841) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 24641254 + ... + 24641306.

It is an arithmetic number, because the mean of its divisors is an integer number (8830080).

Almost surely, 2^1305987840 is an apocalyptic number.

1305987840 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 1305987840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2543063040).

1305987840 is an abundant number, since it is smaller than the sum of its proper divisors (3780138240).

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

1305987840 is a wasteful number, since it uses less digits than its factorization.

1305987840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The square root of 1305987840 is about 36138.4537577357. The cubic root of 1305987840 is about 1093.0659799727.

The spelling of 1305987840 in words is "one billion, three hundred five million, nine hundred eighty-seven thousand, eight hundred forty".