19420209 has 8 divisors (see below), whose sum is σ = 28770720. Its totient is φ = 12946788.

The previous prime is 19420201. The next prime is 19420217. The reversal of 19420209 is 90202491.

It is an interprime number because it is at equal distance from previous prime (19420201) and next prime (19420217).

It is not a de Polignac number, because 19420209 - 2³ = 19420201 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 719267 = 19420209 / (1 + 9 + 4 + 2 + 0 + 2 + 0 + 9).

It is not an unprimeable number, because it can be changed into a prime (19420201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 359607 + ... + 359660.

It is an arithmetic number, because the mean of its divisors is an integer number (3596340).

Almost surely, 2^19420209 is an apocalyptic number.

It is an amenable number.

19420209 is a deficient number, since it is larger than the sum of its proper divisors (9350511).

19420209 is an equidigital number, since it uses as much as digits as its factorization.

19420209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 719276 (or 719270 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 19420209 is about 4406.8366205250. The cubic root of 19420209 is about 268.7930074313.

The spelling of 19420209 in words is "nineteen million, four hundred twenty thousand, two hundred nine".