190506809 has 2 divisors, whose sum is σ = 190506810. Its totient is φ = 190506808.

The previous prime is 190506803. The next prime is 190506847. The reversal of 190506809 is 908605091.

It is an a-pointer prime, because the next prime (190506847) can be obtained adding 190506809 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 134676025 + 55830784 = 11605^2 + 7472^2 .

It is a cyclic number.

It is not a de Polignac number, because 190506809 - 2⁴ = 190506793 is a prime.

It is not a weakly prime, because it can be changed into another prime (190506803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95253404 + 95253405.

It is an arithmetic number, because the mean of its divisors is an integer number (95253405).

Almost surely, 2^190506809 is an apocalyptic number.

It is an amenable number.

190506809 is a deficient number, since it is larger than the sum of its proper divisors (1).

190506809 is an equidigital number, since it uses as much as digits as its factorization.

190506809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19440, while the sum is 38.

The square root of 190506809 is about 13802.4204036828. The cubic root of 190506809 is about 575.4004107057.

The spelling of 190506809 in words is "one hundred ninety million, five hundred six thousand, eight hundred nine".