209144939 has 2 divisors, whose sum is σ = 209144940. Its totient is φ = 209144938.

The previous prime is 209144909. The next prime is 209144981. The reversal of 209144939 is 939441902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 209144939 - 2¹² = 209140843 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 209144896 and 209144905.

It is not a weakly prime, because it can be changed into another prime (209144909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104572469 + 104572470.

It is an arithmetic number, because the mean of its divisors is an integer number (104572470).

Almost surely, 2^209144939 is an apocalyptic number.

209144939 is a deficient number, since it is larger than the sum of its proper divisors (1).

209144939 is an equidigital number, since it uses as much as digits as its factorization.

209144939 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69984, while the sum is 41.

The square root of 209144939 is about 14461.8442461534. The cubic root of 209144939 is about 593.5843651887.

The spelling of 209144939 in words is "two hundred nine million, one hundred forty-four thousand, nine hundred thirty-nine".