149857209 has 10 divisors (see below), whose sum is σ = 223860890. Its totient is φ = 99904752.

The previous prime is 149857207. The next prime is 149857217. The reversal of 149857209 is 902758941.

It can be written as a sum of positive squares in only one way, i.e., 140493609 + 9363600 = 11853^2 + 3060^2 .

It is not a de Polignac number, because 149857209 - 2¹ = 149857207 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (149857207) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 924964 + ... + 925125.

It is an arithmetic number, because the mean of its divisors is an integer number (22386089).

Almost surely, 2^149857209 is an apocalyptic number.

It is an amenable number.

149857209 is a deficient number, since it is larger than the sum of its proper divisors (74003681).

149857209 is an equidigital number, since it uses as much as digits as its factorization.

149857209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1850101 (or 1850092 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The square root of 149857209 is about 12241.6179077767. The cubic root of 149857209 is about 531.1606331983.

The spelling of 149857209 in words is "one hundred forty-nine million, eight hundred fifty-seven thousand, two hundred nine".