121765609 has 4 divisors (see below), whose sum is σ = 139160704. Its totient is φ = 104370516.

The previous prime is 121765583. The next prime is 121765621. The reversal of 121765609 is 906567121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 121765609 - 2¹¹ = 121763561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121765649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8697537 + ... + 8697550.

It is an arithmetic number, because the mean of its divisors is an integer number (34790176).

Almost surely, 2^121765609 is an apocalyptic number.

It is an amenable number.

121765609 is a deficient number, since it is larger than the sum of its proper divisors (17395095).

121765609 is an equidigital number, since it uses as much as digits as its factorization.

121765609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17395094.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 121765609 is about 11034.7455339940. The cubic root of 121765609 is about 495.6497388935.

The spelling of 121765609 in words is "one hundred twenty-one million, seven hundred sixty-five thousand, six hundred nine".