1331505779268 has 144 divisors (see below), whose sum is σ = 3640323907584. Its totient is φ = 377671694400.

The previous prime is 1331505779267. The next prime is 1331505779269. The reversal of 1331505779268 is 8629775051331.

It is an interprime number because it is at equal distance from previous prime (1331505779267) and next prime (1331505779269).

It is not an unprimeable number, because it can be changed into a prime (1331505779267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 177838621 + ... + 177846107.

It is an arithmetic number, because the mean of its divisors is an integer number (25280027136).

Almost surely, 2^{1331505779268} 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 1331505779268, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1820161953792).

1331505779268 is an abundant number, since it is smaller than the sum of its proper divisors (2308818128316).

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

1331505779268 is a wasteful number, since it uses less digits than its factorization.

1331505779268 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9662 (or 9653 counting only the distinct ones).

The product of its (nonzero) digits is 9525600, while the sum is 57.

The spelling of 1331505779268 in words is "one trillion, three hundred thirty-one billion, five hundred five million, seven hundred seventy-nine thousand, two hundred sixty-eight".