2191718448864 has 432 divisors, whose sum is σ = 7307633576880. Its totient is φ = 621268623360.

The previous prime is 2191718448847. The next prime is 2191718448869. The reversal of 2191718448864 is 4688448171912.

2191718448864 is a `hidden beast` number, since 2 + 1 + 9 + 1 + 71 + 84 + 488 + 6 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

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 (2191718448869) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2150851747 + ... + 2150852765.

It is an arithmetic number, because the mean of its divisors is an integer number (16915818465).

Almost surely, 2^{2191718448864} is an apocalyptic number.

2191718448864 is a gapful number since it is divisible by the number (24) 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 2191718448864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3653816788440).

2191718448864 is an abundant number, since it is smaller than the sum of its proper divisors (5115915128016).

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

2191718448864 is a wasteful number, since it uses less digits than its factorization.

2191718448864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2103 (or 2085 counting only the distinct ones).

The product of its digits is 24772608, while the sum is 63.

The spelling of 2191718448864 in words is "two trillion, one hundred ninety-one billion, seven hundred eighteen million, four hundred forty-eight thousand, eight hundred sixty-four".