2166565782240 has 768 divisors, whose sum is σ = 7868286397440. Its totient is φ = 556517744640.

The previous prime is 2166565782229. The next prime is 2166565782299. The reversal of 2166565782240 is 422875656612.

2166565782240 is a `hidden beast` number, since 2 + 1 + 6 + 6 + 5 + 6 + 578 + 22 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 4890667459 + ... + 4890667901.

It is an arithmetic number, because the mean of its divisors is an integer number (10245164580).

Almost surely, 2^{2166565782240} is an apocalyptic number.

2166565782240 is a gapful number since it is divisible by the number (20) 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 2166565782240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3934143198720).

2166565782240 is an abundant number, since it is smaller than the sum of its proper divisors (5701720615200).

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

2166565782240 is a wasteful number, since it uses less digits than its factorization.

2166565782240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 872 (or 858 counting only the distinct ones).

The product of its (nonzero) digits is 9676800, while the sum is 54.

The spelling of 2166565782240 in words is "two trillion, one hundred sixty-six billion, five hundred sixty-five million, seven hundred eighty-two thousand, two hundred forty".