209240819 has 2 divisors, whose sum is σ = 209240820. Its totient is φ = 209240818.

The previous prime is 209240803. The next prime is 209240827. The reversal of 209240819 is 918042902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 209240819 - 2⁴ = 209240803 is a prime.

It is a super-2 number, since 2×209240819² = 87563440671581522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (209240839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104620409 + 104620410.

It is an arithmetic number, because the mean of its divisors is an integer number (104620410).

Almost surely, 2^209240819 is an apocalyptic number.

209240819 is a deficient number, since it is larger than the sum of its proper divisors (1).

209240819 is an equidigital number, since it uses as much as digits as its factorization.

209240819 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 209240819 is about 14465.1587962248. The cubic root of 209240819 is about 593.6750585526.

The spelling of 209240819 in words is "two hundred nine million, two hundred forty thousand, eight hundred nineteen".