1296138648 has 64 divisors (see below), whose sum is σ = 3722146560. Its totient is φ = 368436096.

The previous prime is 1296138643. The next prime is 1296138659. The reversal of 1296138648 is 8468316921.

It is a junction number, because it is equal to n+sod(n) for n = 1296138597 and 1296138606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1296138643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13515 + ... + 52677.

It is an arithmetic number, because the mean of its divisors is an integer number (58158540).

Almost surely, 2^1296138648 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1296138648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1861073280).

1296138648 is an abundant number, since it is smaller than the sum of its proper divisors (2426007912).

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

1296138648 is a wasteful number, since it uses less digits than its factorization.

1296138648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39376 (or 39372 counting only the distinct ones).

The product of its digits is 497664, while the sum is 48.

The square root of 1296138648 is about 36001.9256151668. The cubic root of 1296138648 is about 1090.3112339635.

The spelling of 1296138648 in words is "one billion, two hundred ninety-six million, one hundred thirty-eight thousand, six hundred forty-eight".