121785505 has 4 divisors (see below), whose sum is σ = 146142612. Its totient is φ = 97428400.

The previous prime is 121785487. The next prime is 121785523. The reversal of 121785505 is 505587121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 505587121 = 13 ⋅38891317.

It is an interprime number because it is at equal distance from previous prime (121785487) and next prime (121785523).

It can be written as a sum of positive squares in 2 ways, for example, as 86881041 + 34904464 = 9321^2 + 5908^2 .

It is a de Polignac number, because none of the positive numbers 2^k-121785505 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 12178546 + ... + 12178555.

It is an arithmetic number, because the mean of its divisors is an integer number (36535653).

Almost surely, 2^121785505 is an apocalyptic number.

It is an amenable number.

121785505 is a deficient number, since it is larger than the sum of its proper divisors (24357107).

121785505 is an equidigital number, since it uses as much as digits as its factorization.

121785505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24357106.

The product of its (nonzero) digits is 14000, while the sum is 34.

The square root of 121785505 is about 11035.6470132023. The cubic root of 121785505 is about 495.6767331333.

The spelling of 121785505 in words is "one hundred twenty-one million, seven hundred eighty-five thousand, five hundred five".