6605878261 has 4 divisors (see below), whose sum is σ = 6608193292. Its totient is φ = 6603563232.

The previous prime is 6605878229. The next prime is 6605878283. The reversal of 6605878261 is 1628785066.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5301296100 + 1304582161 = 72810^2 + 36119^2 .

It is a cyclic number.

It is not a de Polignac number, because 6605878261 - 2⁵ = 6605878229 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6605878291) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1153230 + ... + 1158943.

It is an arithmetic number, because the mean of its divisors is an integer number (1652048323).

Almost surely, 2^6605878261 is an apocalyptic number.

It is an amenable number.

6605878261 is a deficient number, since it is larger than the sum of its proper divisors (2315031).

6605878261 is a wasteful number, since it uses less digits than its factorization.

6605878261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2315030.

The product of its (nonzero) digits is 967680, while the sum is 49.

The square root of 6605878261 is about 81276.5541900000. The cubic root of 6605878261 is about 1876.3341744360.

The spelling of 6605878261 in words is "six billion, six hundred five million, eight hundred seventy-eight thousand, two hundred sixty-one".