1216513121 has 8 divisors (see below), whose sum is σ = 1261525824. Its totient is φ = 1172139120.

The previous prime is 1216513093. The next prime is 1216513163. The reversal of 1216513121 is 1213156121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1216513121 - 2¹⁴ = 1216496737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1216510121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 155795 + ... + 163416.

It is an arithmetic number, because the mean of its divisors is an integer number (157690728).

Almost surely, 2^1216513121 is an apocalyptic number.

It is an amenable number.

1216513121 is a deficient number, since it is larger than the sum of its proper divisors (45012703).

1216513121 is a wasteful number, since it uses less digits than its factorization.

1216513121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319351.

The product of its digits is 360, while the sum is 23.

The square root of 1216513121 is about 34878.5481492564. The cubic root of 1216513121 is about 1067.5107713722.

Adding to 1216513121 its reverse (1213156121), we get a palindrome (2429669242).

The spelling of 1216513121 in words is "one billion, two hundred sixteen million, five hundred thirteen thousand, one hundred twenty-one".