137509909 has 4 divisors (see below), whose sum is σ = 142251660. Its totient is φ = 132768160.

The previous prime is 137509903. The next prime is 137509919. The reversal of 137509909 is 909905731.

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 59629284 + 77880625 = 7722^2 + 8825^2 .

It is a cyclic number.

It is not a de Polignac number, because 137509909 - 2³ = 137509901 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (137509901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2370832 + ... + 2370889.

It is an arithmetic number, because the mean of its divisors is an integer number (35562915).

Almost surely, 2^137509909 is an apocalyptic number.

It is an amenable number.

137509909 is a deficient number, since it is larger than the sum of its proper divisors (4741751).

137509909 is an equidigital number, since it uses as much as digits as its factorization.

137509909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4741750.

The product of its (nonzero) digits is 76545, while the sum is 43.

The square root of 137509909 is about 11726.4619131262. The cubic root of 137509909 is about 516.1524560530.

The spelling of 137509909 in words is "one hundred thirty-seven million, five hundred nine thousand, nine hundred nine".