1216257257 has 2 divisors, whose sum is σ = 1216257258. Its totient is φ = 1216257256.

The previous prime is 1216257253. The next prime is 1216257271. The reversal of 1216257257 is 7527526121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1187215936 + 29041321 = 34456^2 + 5389^2 .

It is a cyclic number.

It is not a de Polignac number, because 1216257257 - 2² = 1216257253 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1216257257.

It is not a weakly prime, because it can be changed into another prime (1216257253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608128628 + 608128629.

It is an arithmetic number, because the mean of its divisors is an integer number (608128629).

Almost surely, 2^1216257257 is an apocalyptic number.

It is an amenable number.

1216257257 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216257257 is an equidigital number, since it uses as much as digits as its factorization.

1216257257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 58800, while the sum is 38.

The square root of 1216257257 is about 34874.8800284675. The cubic root of 1216257257 is about 1067.4359244668.

The spelling of 1216257257 in words is "one billion, two hundred sixteen million, two hundred fifty-seven thousand, two hundred fifty-seven".