148691909 has 2 divisors, whose sum is σ = 148691910. Its totient is φ = 148691908.

The previous prime is 148691887. The next prime is 148691923. The reversal of 148691909 is 909196841.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 147136900 + 1555009 = 12130^2 + 1247^2 .

It is a cyclic number.

It is not a de Polignac number, because 148691909 - 2²⁰ = 147643333 is a prime.

It is a Sophie Germain 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 (148691969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 74345954 + 74345955.

It is an arithmetic number, because the mean of its divisors is an integer number (74345955).

Almost surely, 2^148691909 is an apocalyptic number.

It is an amenable number.

148691909 is a deficient number, since it is larger than the sum of its proper divisors (1).

148691909 is an equidigital number, since it uses as much as digits as its factorization.

148691909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 139968, while the sum is 47.

The square root of 148691909 is about 12193.9291862795. The cubic root of 148691909 is about 529.7802684731.

The spelling of 148691909 in words is "one hundred forty-eight million, six hundred ninety-one thousand, nine hundred nine".