121312665 has 12 divisors (see below), whose sum is σ = 210275364. Its totient is φ = 64700064.

The previous prime is 121312657. The next prime is 121312691. The reversal of 121312665 is 566213121.

It can be written as a sum of positive squares in 2 ways, for example, as 36433296 + 84879369 = 6036^2 + 9213^2 .

It is not a de Polignac number, because 121312665 - 2³ = 121312657 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1347874 + ... + 1347963.

It is an arithmetic number, because the mean of its divisors is an integer number (17522947).

Almost surely, 2^121312665 is an apocalyptic number.

121312665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121312665 is a deficient number, since it is larger than the sum of its proper divisors (88962699).

121312665 is a wasteful number, since it uses less digits than its factorization.

121312665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2695848 (or 2695845 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 121312665 is about 11014.2028762866. The cubic root of 121312665 is about 495.0344022616.

Adding to 121312665 its reverse (566213121), we get a palindrome (687525786).

The spelling of 121312665 in words is "one hundred twenty-one million, three hundred twelve thousand, six hundred sixty-five".