1296545640 has 128 divisors (see below), whose sum is σ = 4198037760. Its totient is φ = 318449664.

The previous prime is 1296545611. The next prime is 1296545651. The reversal of 1296545640 is 465456921.

It is a junction number, because it is equal to n+sod(n) for n = 1296545592 and 1296545601.

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 31 ways as a sum of consecutive naturals, for example, 1383252 + ... + 1384188.

It is an arithmetic number, because the mean of its divisors is an integer number (32797170).

Almost surely, 2^1296545640 is an apocalyptic number.

1296545640 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 1296545640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2099018880).

1296545640 is an abundant number, since it is smaller than the sum of its proper divisors (2901492120).

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

1296545640 is a wasteful number, since it uses less digits than its factorization.

1296545640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1851 (or 1847 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 42.

The square root of 1296545640 is about 36007.5775358465. The cubic root of 1296545640 is about 1090.4253425152.

The spelling of 1296545640 in words is "one billion, two hundred ninety-six million, five hundred forty-five thousand, six hundred forty".