189709805 has 8 divisors (see below), whose sum is σ = 227922552. Its totient is φ = 151587328.

The previous prime is 189709733. The next prime is 189709811. The reversal of 189709805 is 508907981.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 18335524 + 171374281 = 4282^2 + 13091^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 189709805 - 2⁸ = 189709549 is a prime.

It is a super-2 number, since 2×189709805² = 71979620226276050, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 189709805.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17852 + ... + 26421.

It is an arithmetic number, because the mean of its divisors is an integer number (28490319).

Almost surely, 2^189709805 is an apocalyptic number.

It is an amenable number.

189709805 is a deficient number, since it is larger than the sum of its proper divisors (38212747).

189709805 is an equidigital number, since it uses as much as digits as its factorization.

189709805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45135.

The product of its (nonzero) digits is 181440, while the sum is 47.

The square root of 189709805 is about 13773.5182506141. The cubic root of 189709805 is about 574.5968743393.

The spelling of 189709805 in words is "one hundred eighty-nine million, seven hundred nine thousand, eight hundred five".