843550661 has 2 divisors, whose sum is σ = 843550662. Its totient is φ = 843550660.

The previous prime is 843550627. The next prime is 843550699. The reversal of 843550661 is 166055348.

It is an a-pointer prime, because the next prime (843550699) can be obtained adding 843550661 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 823345636 + 20205025 = 28694^2 + 4495^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-843550661 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (843550061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 421775330 + 421775331.

It is an arithmetic number, because the mean of its divisors is an integer number (421775331).

Almost surely, 2^843550661 is an apocalyptic number.

It is an amenable number.

843550661 is a deficient number, since it is larger than the sum of its proper divisors (1).

843550661 is an equidigital number, since it uses as much as digits as its factorization.

843550661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 86400, while the sum is 38.

The square root of 843550661 is about 29043.9436199701. The cubic root of 843550661 is about 944.8663663298.

The spelling of 843550661 in words is "eight hundred forty-three million, five hundred fifty thousand, six hundred sixty-one".