1298765440 has 128 divisors (see below), whose sum is σ = 3577115520. Its totient is φ = 441692160.

The previous prime is 1298765423. The next prime is 1298765443. The reversal of 1298765440 is 445678921.

It is a tau number, because it is divible by the number of its divisors (128).

It is not an unprimeable number, because it can be changed into a prime (1298765443) 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 15 ways as a sum of consecutive naturals, for example, 585774 + ... + 587986.

It is an arithmetic number, because the mean of its divisors is an integer number (27946215).

Almost surely, 2^1298765440 is an apocalyptic number.

1298765440 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 1298765440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1788557760).

1298765440 is an abundant number, since it is smaller than the sum of its proper divisors (2278350080).

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

1298765440 is a wasteful number, since it uses less digits than its factorization.

1298765440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2370 (or 2358 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 46.

The square root of 1298765440 is about 36038.3884212377. The cubic root of 1298765440 is about 1091.0472890241.

The spelling of 1298765440 in words is "one billion, two hundred ninety-eight million, seven hundred sixty-five thousand, four hundred forty".