1217121516 has 36 divisors (see below), whose sum is σ = 3313276512. Its totient is φ = 374498784.

The previous prime is 1217121431. The next prime is 1217121517. The reversal of 1217121516 is 6151217121.

1217121516 is a `hidden beast` number, since 1 + 21 + 7 + 121 + 516 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a self number, because there is not a number n which added to its sum of digits gives 1217121516.

It is not an unprimeable number, because it can be changed into a prime (1217121517) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1299876 + ... + 1300811.

Almost surely, 2^1217121516 is an apocalyptic number.

It is an amenable number.

1217121516 is an abundant number, since it is smaller than the sum of its proper divisors (2096154996).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1217121516 is a wasteful number, since it uses less digits than its factorization.

1217121516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2600710 (or 2600705 counting only the distinct ones).

The product of its digits is 840, while the sum is 27.

The square root of 1217121516 is about 34887.2686807093. The cubic root of 1217121516 is about 1067.6887006701.

Adding to 1217121516 its reverse (6151217121), we get a palindrome (7368338637).

The spelling of 1217121516 in words is "one billion, two hundred seventeen million, one hundred twenty-one thousand, five hundred sixteen".