149685509 has 2 divisors, whose sum is σ = 149685510. Its totient is φ = 149685508.

The previous prime is 149685469. The next prime is 149685517. The reversal of 149685509 is 905586941.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 147501025 + 2184484 = 12145^2 + 1478^2 .

It is a cyclic number.

It is not a de Polignac number, because 149685509 - 2¹⁶ = 149619973 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (149685539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 74842754 + 74842755.

It is an arithmetic number, because the mean of its divisors is an integer number (74842755).

Almost surely, 2^149685509 is an apocalyptic number.

It is an amenable number.

149685509 is a deficient number, since it is larger than the sum of its proper divisors (1).

149685509 is an equidigital number, since it uses as much as digits as its factorization.

149685509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 388800, while the sum is 47.

The square root of 149685509 is about 12234.6029359354. The cubic root of 149685509 is about 530.9576952712.

The spelling of 149685509 in words is "one hundred forty-nine million, six hundred eighty-five thousand, five hundred nine".