149191909 has 4 divisors (see below), whose sum is σ = 151637740. Its totient is φ = 146746080.

The previous prime is 149191901. The next prime is 149191937. The reversal of 149191909 is 909191941.

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 51122500 + 98069409 = 7150^2 + 9903^2 .

It is a cyclic number.

It is not a de Polignac number, because 149191909 - 2³ = 149191901 is a prime.

It is a super-2 number, since 2×149191909² = 44516451422128562, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (149191901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1222824 + ... + 1222945.

It is an arithmetic number, because the mean of its divisors is an integer number (37909435).

Almost surely, 2^149191909 is an apocalyptic number.

It is an amenable number.

149191909 is a deficient number, since it is larger than the sum of its proper divisors (2445831).

149191909 is an equidigital number, since it uses as much as digits as its factorization.

149191909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2445830.

The product of its (nonzero) digits is 26244, while the sum is 43.

The square root of 149191909 is about 12214.4139851243. The cubic root of 149191909 is about 530.3734273474.

The spelling of 149191909 in words is "one hundred forty-nine million, one hundred ninety-one thousand, nine hundred nine".