6661133261 has 2 divisors, whose sum is σ = 6661133262. Its totient is φ = 6661133260.

The previous prime is 6661133231. The next prime is 6661133317. The reversal of 6661133261 is 1623311666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4404313225 + 2256820036 = 66365^2 + 47506^2 .

It is a cyclic number.

It is not a de Polignac number, because 6661133261 - 2²² = 6656938957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6661133231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3330566630 + 3330566631.

It is an arithmetic number, because the mean of its divisors is an integer number (3330566631).

Almost surely, 2^6661133261 is an apocalyptic number.

It is an amenable number.

6661133261 is a deficient number, since it is larger than the sum of its proper divisors (1).

6661133261 is an equidigital number, since it uses as much as digits as its factorization.

6661133261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23328, while the sum is 35.

The square root of 6661133261 is about 81615.7660075552. The cubic root of 6661133261 is about 1881.5512002202.

The spelling of 6661133261 in words is "six billion, six hundred sixty-one million, one hundred thirty-three thousand, two hundred sixty-one".