1311917281920 has 1536 divisors, whose sum is σ = 5633235763200. Its totient is φ = 287400960000.

The previous prime is 1311917281903. The next prime is 1311917281993. The reversal of 1311917281920 is 291827191131.

1311917281920 is a `hidden beast` number, since 1 + 311 + 9 + 172 + 81 + 92 + 0 = 666.

It is a super-2 number, since 2×1311917281920² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 3963496155 + ... + 3963496485.

It is an arithmetic number, because the mean of its divisors is an integer number (3667471200).

Almost surely, 2^{1311917281920} is an apocalyptic number.

1311917281920 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 1311917281920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2816617881600).

1311917281920 is an abundant number, since it is smaller than the sum of its proper divisors (4321318481280).

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

1311917281920 is a wasteful number, since it uses less digits than its factorization.

1311917281920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 555 (or 530 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 45.

The spelling of 1311917281920 in words is "one trillion, three hundred eleven billion, nine hundred seventeen million, two hundred eighty-one thousand, nine hundred twenty".