1305123456 has 320 divisors, whose sum is σ = 4544614080. Its totient is φ = 323960832.

The previous prime is 1305123451. The next prime is 1305123481. The reversal of 1305123456 is 6543215031.

It is not an unprimeable number, because it can be changed into a prime (1305123451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 76771960 + ... + 76771976.

It is an arithmetic number, because the mean of its divisors is an integer number (14201919).

Almost surely, 2^1305123456 is an apocalyptic number.

1305123456 is a gapful number since it is divisible by the number (16) 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 1305123456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2272307040).

1305123456 is an abundant number, since it is smaller than the sum of its proper divisors (3239490624).

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

1305123456 is an frugal number, since it uses more digits than its factorization.

1305123456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93 (or 42 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 30.

The square root of 1305123456 is about 36126.4924397595. The cubic root of 1305123456 is about 1092.8247737274.

Adding to 1305123456 its reverse (6543215031), we get a palindrome (7848338487).

The spelling of 1305123456 in words is "one billion, three hundred five million, one hundred twenty-three thousand, four hundred fifty-six".