661136243 has 2 divisors, whose sum is σ = 661136244. Its totient is φ = 661136242.

The previous prime is 661136237. The next prime is 661136261. The reversal of 661136243 is 342631166.

661136243 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 661136243 - 2¹⁴ = 661119859 is a prime.

It is a super-2 number, since 2×661136243² = 874202263616310098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (661136213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330568121 + 330568122.

It is an arithmetic number, because the mean of its divisors is an integer number (330568122).

Almost surely, 2^661136243 is an apocalyptic number.

661136243 is a deficient number, since it is larger than the sum of its proper divisors (1).

661136243 is an equidigital number, since it uses as much as digits as its factorization.

661136243 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 32.

The square root of 661136243 is about 25712.5697471101. The cubic root of 661136243 is about 871.1581189991.

The spelling of 661136243 in words is "six hundred sixty-one million, one hundred thirty-six thousand, two hundred forty-three".