243990189 has 6 divisors (see below), whose sum is σ = 352430286. Its totient is φ = 162660120.

The previous prime is 243990169. The next prime is 243990209. The reversal of 243990189 is 981099342.

It is an interprime number because it is at equal distance from previous prime (243990169) and next prime (243990209).

It can be written as a sum of positive squares in only one way, i.e., 128255625 + 115734564 = 11325^2 + 10758^2 .

It is not a de Polignac number, because 243990189 - 2¹⁷ = 243859117 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243990169) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13555002 + ... + 13555019.

It is an arithmetic number, because the mean of its divisors is an integer number (58738381).

Almost surely, 2^243990189 is an apocalyptic number.

It is an amenable number.

243990189 is a deficient number, since it is larger than the sum of its proper divisors (108440097).

243990189 is a wasteful number, since it uses less digits than its factorization.

243990189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27110027 (or 27110024 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 45.

The square root of 243990189 is about 15620.1853061992. The cubic root of 243990189 is about 624.8716015706.

The spelling of 243990189 in words is "two hundred forty-three million, nine hundred ninety thousand, one hundred eighty-nine".