2165578771764 has 48 divisors (see below), whose sum is σ = 5129192678400. Its totient is φ = 711020989536.

The previous prime is 2165578771721. The next prime is 2165578771787. The reversal of 2165578771764 is 4671778755612.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 2165578771695 and 2165578771704.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2328762 + ... + 3123185.

It is an arithmetic number, because the mean of its divisors is an integer number (106858180800).

Almost surely, 2^{2165578771764} is an apocalyptic number.

It is an amenable number.

2165578771764 is an abundant number, since it is smaller than the sum of its proper divisors (2963613906636).

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

2165578771764 is a wasteful number, since it uses less digits than its factorization.

2165578771764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5452452 (or 5452450 counting only the distinct ones).

The product of its digits is 138297600, while the sum is 66.

The spelling of 2165578771764 in words is "two trillion, one hundred sixty-five billion, five hundred seventy-eight million, seven hundred seventy-one thousand, seven hundred sixty-four".