243133661 has 2 divisors, whose sum is σ = 243133662. Its totient is φ = 243133660.

The previous prime is 243133637. The next prime is 243133673. The reversal of 243133661 is 166331342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 187854436 + 55279225 = 13706^2 + 7435^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243133661 is a prime.

It is a super-2 number, since 2×243133661² = 118227954222525842, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243133691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121566830 + 121566831.

It is an arithmetic number, because the mean of its divisors is an integer number (121566831).

Almost surely, 2^243133661 is an apocalyptic number.

It is an amenable number.

243133661 is a deficient number, since it is larger than the sum of its proper divisors (1).

243133661 is an equidigital number, since it uses as much as digits as its factorization.

243133661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 29.

The square root of 243133661 is about 15592.7438573203. The cubic root of 243133661 is about 624.1395399706.

The spelling of 243133661 in words is "two hundred forty-three million, one hundred thirty-three thousand, six hundred sixty-one".