1216011321 has 12 divisors (see below), whose sum is σ = 2007383872. Its totient is φ = 694863576.

The previous prime is 1216011289. The next prime is 1216011347. The reversal of 1216011321 is 1231106121.

1216011321 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1216011321 - 2⁵ = 1216011289 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1216011294 and 1216011303.

It is not an unprimeable number, because it can be changed into a prime (1216011721) 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, 9650821 + ... + 9650946.

Almost surely, 2^1216011321 is an apocalyptic number.

It is an amenable number.

1216011321 is a deficient number, since it is larger than the sum of its proper divisors (791372551).

1216011321 is a wasteful number, since it uses less digits than its factorization.

1216011321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19301780 (or 19301777 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 1216011321 is about 34871.3538739178. The cubic root of 1216011321 is about 1067.3639718661.

Adding to 1216011321 its reverse (1231106121), we get a palindrome (2447117442).

The spelling of 1216011321 in words is "one billion, two hundred sixteen million, eleven thousand, three hundred twenty-one".