1313261921664 has 768 divisors, whose sum is σ = 4955500892160. Its totient is φ = 336259123200.

The previous prime is 1313261921663. The next prime is 1313261921717. The reversal of 1313261921664 is 4661291623131.

1313261921664 is a `hidden beast` number, since 1 + 3 + 1 + 3 + 2 + 619 + 21 + 6 + 6 + 4 = 666.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1313261921663) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 170041707 + ... + 170049429.

It is an arithmetic number, because the mean of its divisors is an integer number (6452475120).

Almost surely, 2^{1313261921664} is an apocalyptic number.

1313261921664 is a gapful number since it is divisible by the number (14) 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 1313261921664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2477750446080).

1313261921664 is an abundant number, since it is smaller than the sum of its proper divisors (3642238970496).

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

1313261921664 is an equidigital number, since it uses as much as digits as its factorization.

1313261921664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7841 (or 7817 counting only the distinct ones).

The product of its digits is 279936, while the sum is 45.

The spelling of 1313261921664 in words is "one trillion, three hundred thirteen billion, two hundred sixty-one million, nine hundred twenty-one thousand, six hundred sixty-four".