6656011261 has 4 divisors (see below), whose sum is σ = 6656258752. Its totient is φ = 6655763772.

The previous prime is 6656011231. The next prime is 6656011273. The reversal of 6656011261 is 1621106566.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1621106566 = 2 ⋅810553283.

It is a cyclic number.

It is not a de Polignac number, because 6656011261 - 2⁷ = 6656011133 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 (6656011231) 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, 77691 + ... + 139096.

It is an arithmetic number, because the mean of its divisors is an integer number (1664064688).

Almost surely, 2^6656011261 is an apocalyptic number.

It is an amenable number.

6656011261 is a deficient number, since it is larger than the sum of its proper divisors (247491).

6656011261 is a wasteful number, since it uses less digits than its factorization.

6656011261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247490.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 6656011261 is about 81584.3812319490. The cubic root of 6656011261 is about 1881.0688110085.

The spelling of 6656011261 in words is "six billion, six hundred fifty-six million, eleven thousand, two hundred sixty-one".