1287305440 has 24 divisors (see below), whose sum is σ = 3041259480. Its totient is φ = 514922112.

The previous prime is 1287305417. The next prime is 1287305441. The reversal of 1287305440 is 445037821.

It is a junction number, because it is equal to n+sod(n) for n = 1287305396 and 1287305405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1287305441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4022670 + ... + 4022989.

It is an arithmetic number, because the mean of its divisors is an integer number (126719145).

Almost surely, 2^1287305440 is an apocalyptic number.

1287305440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1287305440 is an abundant number, since it is smaller than the sum of its proper divisors (1753954040).

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

1287305440 is an equidigital number, since it uses as much as digits as its factorization.

1287305440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8045674 (or 8045666 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 34.

The square root of 1287305440 is about 35879.0390060826. The cubic root of 1287305440 is about 1087.8287558486.

The spelling of 1287305440 in words is "one billion, two hundred eighty-seven million, three hundred five thousand, four hundred forty".