149491809 has 12 divisors (see below), whose sum is σ = 218891556. Its totient is φ = 98295552.

The previous prime is 149491777. The next prime is 149491813. The reversal of 149491809 is 908194941.

It can be written as a sum of positive squares in 2 ways, for example, as 124211025 + 25280784 = 11145^2 + 5028^2 .

It is not a de Polignac number, because 149491809 - 2⁵ = 149491777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (149491109) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 113112 + ... + 114425.

It is an arithmetic number, because the mean of its divisors is an integer number (18240963).

Almost surely, 2^149491809 is an apocalyptic number.

It is an amenable number.

149491809 is a deficient number, since it is larger than the sum of its proper divisors (69399747).

149491809 is a wasteful number, since it uses less digits than its factorization.

149491809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227616 (or 227613 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The square root of 149491809 is about 12226.6843011505. The cubic root of 149491809 is about 530.7285684374.

The spelling of 149491809 in words is "one hundred forty-nine million, four hundred ninety-one thousand, eight hundred nine".