2665563156 has 18 divisors (see below), whose sum is σ = 6737951402. Its totient is φ = 888521040.

The previous prime is 2665563151. The next prime is 2665563157. The reversal of 2665563156 is 6513655662.

2665563156 is a `hidden beast` number, since 2 + 6 + 6 + 5 + 5 + 631 + 5 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2128899600 + 536663556 = 46140^2 + 23166^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2665563151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37021675 + ... + 37021746.

Almost surely, 2^2665563156 is an apocalyptic number.

It is an amenable number.

2665563156 is an abundant number, since it is smaller than the sum of its proper divisors (4072388246).

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

2665563156 is a wasteful number, since it uses less digits than its factorization.

2665563156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74043431 (or 74043426 counting only the distinct ones).

The product of its digits is 972000, while the sum is 45.

The square root of 2665563156 is about 51629.0921477417. The cubic root of 2665563156 is about 1386.5312394193.

The spelling of 2665563156 in words is "two billion, six hundred sixty-five million, five hundred sixty-three thousand, one hundred fifty-six".