149439209 has 2 divisors, whose sum is σ = 149439210. Its totient is φ = 149439208.

The previous prime is 149439187. The next prime is 149439221. The reversal of 149439209 is 902934941.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 148766809 + 672400 = 12197^2 + 820^2 .

It is a cyclic number.

It is not a de Polignac number, because 149439209 - 2⁸ = 149438953 is a prime.

It is not a weakly prime, because it can be changed into another prime (149439709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 74719604 + 74719605.

It is an arithmetic number, because the mean of its divisors is an integer number (74719605).

Almost surely, 2^149439209 is an apocalyptic number.

It is an amenable number.

149439209 is a deficient number, since it is larger than the sum of its proper divisors (1).

149439209 is an equidigital number, since it uses as much as digits as its factorization.

149439209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69984, while the sum is 41.

The square root of 149439209 is about 12224.5330790178. The cubic root of 149439209 is about 530.6663139730. Note that the first 3 decimals are identical.

The spelling of 149439209 in words is "one hundred forty-nine million, four hundred thirty-nine thousand, two hundred nine".