189181009 has 4 divisors (see below), whose sum is σ = 192750516. Its totient is φ = 185611504.

The previous prime is 189180961. The next prime is 189181021. The reversal of 189181009 is 900181981.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 70980625 + 118200384 = 8425^2 + 10872^2 .

It is a cyclic number.

It is not a de Polignac number, because 189181009 - 2²¹ = 187083857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (189181039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1784674 + ... + 1784779.

It is an arithmetic number, because the mean of its divisors is an integer number (48187629).

Almost surely, 2^189181009 is an apocalyptic number.

It is an amenable number.

189181009 is a deficient number, since it is larger than the sum of its proper divisors (3569507).

189181009 is an equidigital number, since it uses as much as digits as its factorization.

189181009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3569506.

The product of its (nonzero) digits is 5184, while the sum is 37.

The square root of 189181009 is about 13754.3087430812. The cubic root of 189181009 is about 574.0625015407.

The spelling of 189181009 in words is "one hundred eighty-nine million, one hundred eighty-one thousand, nine".