1216616965 has 4 divisors (see below), whose sum is σ = 1459940364. Its totient is φ = 973293568.

The previous prime is 1216616959. The next prime is 1216616969. The reversal of 1216616965 is 5696166121.

1216616965 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5696166121 = 41 ⋅138930881.

It can be written as a sum of positive squares in 2 ways, for example, as 807525889 + 409091076 = 28417^2 + 20226^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1216616965 is a prime.

It is a super-2 number, since 2×1216616965² = 2960313679051622450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216616969) 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, 121661692 + ... + 121661701.

It is an arithmetic number, because the mean of its divisors is an integer number (364985091).

Almost surely, 2^1216616965 is an apocalyptic number.

It is an amenable number.

1216616965 is a deficient number, since it is larger than the sum of its proper divisors (243323399).

1216616965 is an equidigital number, since it uses as much as digits as its factorization.

1216616965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243323398.

The product of its digits is 116640, while the sum is 43.

The square root of 1216616965 is about 34880.0367689026. The cubic root of 1216616965 is about 1067.5411454614.

The spelling of 1216616965 in words is "one billion, two hundred sixteen million, six hundred sixteen thousand, nine hundred sixty-five".