1216611653 has 2 divisors, whose sum is σ = 1216611654. Its totient is φ = 1216611652.

The previous prime is 1216611637. The next prime is 1216611679. The reversal of 1216611653 is 3561166121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1069159204 + 147452449 = 32698^2 + 12143^2 .

It is a cyclic number.

It is not a de Polignac number, because 1216611653 - 2⁴ = 1216611637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1216611853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608305826 + 608305827.

It is an arithmetic number, because the mean of its divisors is an integer number (608305827).

Almost surely, 2^1216611653 is an apocalyptic number.

It is an amenable number.

1216611653 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216611653 is an equidigital number, since it uses as much as digits as its factorization.

1216611653 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6480, while the sum is 32.

The square root of 1216611653 is about 34879.9606221108. The cubic root of 1216611653 is about 1067.5395917578.

Adding to 1216611653 its reverse (3561166121), we get a palindrome (4777777774).

The spelling of 1216611653 in words is "one billion, two hundred sixteen million, six hundred eleven thousand, six hundred fifty-three".