1216257757 has 12 divisors (see below), whose sum is σ = 1439717020. Its totient is φ = 1020634560.

The previous prime is 1216257719. The next prime is 1216257769. The reversal of 1216257757 is 7577526121.

It can be written as a sum of positive squares in 2 ways, for example, as 61685316 + 1154572441 = 7854^2 + 33979^2 .

It is not a de Polignac number, because 1216257757 - 2¹⁹ = 1215733469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216257787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 385032 + ... + 388177.

Almost surely, 2^1216257757 is an apocalyptic number.

It is an amenable number.

1216257757 is a deficient number, since it is larger than the sum of its proper divisors (223459263).

1216257757 is a wasteful number, since it uses less digits than its factorization.

1216257757 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 773244 (or 773233 counting only the distinct ones).

The product of its digits is 205800, while the sum is 43.

The square root of 1216257757 is about 34874.8871969502. The cubic root of 1216257757 is about 1067.4360707401.

The spelling of 1216257757 in words is "one billion, two hundred sixteen million, two hundred fifty-seven thousand, seven hundred fifty-seven".