209400019 has 2 divisors, whose sum is σ = 209400020. Its totient is φ = 209400018.

The previous prime is 209399951. The next prime is 209400029. The reversal of 209400019 is 910004902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 209400019 - 2⁷ = 209399891 is a prime.

It is a super-2 number, since 2×209400019² = 87696735914400722, which contains 22 as substring.

It is equal to p_11570128 and since 209400019 and 11570128 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 209399966 and 209400002.

It is not a weakly prime, because it can be changed into another prime (209400029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104700009 + 104700010.

It is an arithmetic number, because the mean of its divisors is an integer number (104700010).

Almost surely, 2^209400019 is an apocalyptic number.

209400019 is a deficient number, since it is larger than the sum of its proper divisors (1).

209400019 is an equidigital number, since it uses as much as digits as its factorization.

209400019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 209400019 is about 14470.6606276286. The cubic root of 209400019 is about 593.8255854430.

The spelling of 209400019 in words is "two hundred nine million, four hundred thousand, nineteen".