239978009 has 2 divisors, whose sum is σ = 239978010. Its totient is φ = 239978008.

The previous prime is 239978003. The next prime is 239978023. The reversal of 239978009 is 900879932.

239978009 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 can be written as a sum of positive squares in only one way, i.e., 236544400 + 3433609 = 15380^2 + 1853^2 .

It is a cyclic number.

It is not a de Polignac number, because 239978009 - 2¹² = 239973913 is a prime.

It is not a weakly prime, because it can be changed into another prime (239978003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 119989004 + 119989005.

It is an arithmetic number, because the mean of its divisors is an integer number (119989005).

Almost surely, 2^239978009 is an apocalyptic number.

It is an amenable number.

239978009 is a deficient number, since it is larger than the sum of its proper divisors (1).

239978009 is an equidigital number, since it uses as much as digits as its factorization.

239978009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 244944, while the sum is 47.

The square root of 239978009 is about 15491.2236120973. The cubic root of 239978009 is about 621.4275197360.

It can be divided in two parts, 2399 and 78009, that added together give a palindrome (80408).

The spelling of 239978009 in words is "two hundred thirty-nine million, nine hundred seventy-eight thousand, nine".