120665509 has 2 divisors, whose sum is σ = 120665510. Its totient is φ = 120665508.

The previous prime is 120665453. The next prime is 120665533. The reversal of 120665509 is 905566021.

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., 106812225 + 13853284 = 10335^2 + 3722^2 .

It is a cyclic number.

It is not a de Polignac number, because 120665509 - 2¹⁵ = 120632741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (120665539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60332754 + 60332755.

It is an arithmetic number, because the mean of its divisors is an integer number (60332755).

Almost surely, 2^120665509 is an apocalyptic number.

It is an amenable number.

120665509 is a deficient number, since it is larger than the sum of its proper divisors (1).

120665509 is an equidigital number, since it uses as much as digits as its factorization.

120665509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16200, while the sum is 34.

The square root of 120665509 is about 10984.7853415531. The cubic root of 120665509 is about 494.1525601462.

The spelling of 120665509 in words is "one hundred twenty million, six hundred sixty-five thousand, five hundred nine".