121505165 has 4 divisors (see below), whose sum is σ = 145806204. Its totient is φ = 97204128.

The previous prime is 121505161. The next prime is 121505191. The reversal of 121505165 is 561505121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13053769 + 108451396 = 3613^2 + 10414^2 .

It is a cyclic number.

It is not a de Polignac number, because 121505165 - 2² = 121505161 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121505161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12150512 + ... + 12150521.

It is an arithmetic number, because the mean of its divisors is an integer number (36451551).

Almost surely, 2^121505165 is an apocalyptic number.

It is an amenable number.

121505165 is a deficient number, since it is larger than the sum of its proper divisors (24301039).

121505165 is an equidigital number, since it uses as much as digits as its factorization.

121505165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24301038.

The product of its (nonzero) digits is 1500, while the sum is 26.

The square root of 121505165 is about 11022.9381291922. The cubic root of 121505165 is about 495.2961055287.

The spelling of 121505165 in words is "one hundred twenty-one million, five hundred five thousand, one hundred sixty-five".