243440397 has 20 divisors (see below), whose sum is σ = 367201120. Its totient is φ = 160712424.

The previous prime is 243440389. The next prime is 243440419. The reversal of 243440397 is 793044342.

243440397 is a `hidden beast` number, since 243 + 4 + 403 + 9 + 7 = 666.

It is not a de Polignac number, because 243440397 - 2³ = 243440389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243440377) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 6247 + ... + 22932.

It is an arithmetic number, because the mean of its divisors is an integer number (18360056).

Almost surely, 2^243440397 is an apocalyptic number.

243440397 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

243440397 is a deficient number, since it is larger than the sum of its proper divisors (123760723).

243440397 is a wasteful number, since it uses less digits than its factorization.

243440397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29294 (or 29285 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 36.

The square root of 243440397 is about 15602.5766141365. The cubic root of 243440397 is about 624.4018999313.

The spelling of 243440397 in words is "two hundred forty-three million, four hundred forty thousand, three hundred ninety-seven".