243409979 has 2 divisors, whose sum is σ = 243409980. Its totient is φ = 243409978.

The previous prime is 243409951. The next prime is 243410003. The reversal of 243409979 is 979904342.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243409979 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (243409079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121704989 + 121704990.

It is an arithmetic number, because the mean of its divisors is an integer number (121704990).

Almost surely, 2^243409979 is an apocalyptic number.

243409979 is a deficient number, since it is larger than the sum of its proper divisors (1).

243409979 is an equidigital number, since it uses as much as digits as its factorization.

243409979 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 489888, while the sum is 47.

The square root of 243409979 is about 15601.6018087887. The cubic root of 243409979 is about 624.3758924043.

The spelling of 243409979 in words is "two hundred forty-three million, four hundred nine thousand, nine hundred seventy-nine".