1216660057 has 2 divisors, whose sum is σ = 1216660058. Its totient is φ = 1216660056.

The previous prime is 1216660051. The next prime is 1216660111. The reversal of 1216660057 is 7500666121.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 856381696 + 360278361 = 29264^2 + 18981^2 .

It is a cyclic number.

It is not a de Polignac number, because 1216660057 - 2¹⁹ = 1216135769 is a prime.

It is not a weakly prime, because it can be changed into another prime (1216660051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608330028 + 608330029.

It is an arithmetic number, because the mean of its divisors is an integer number (608330029).

Almost surely, 2^1216660057 is an apocalyptic number.

It is an amenable number.

1216660057 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216660057 is an equidigital number, since it uses as much as digits as its factorization.

1216660057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 1216660057 is about 34880.6544806717. The cubic root of 1216660057 is about 1067.5537492475.

The spelling of 1216660057 in words is "one billion, two hundred sixteen million, six hundred sixty thousand, fifty-seven".