1216257769 has 2 divisors, whose sum is σ = 1216257770. Its totient is φ = 1216257768.

The previous prime is 1216257719. The next prime is 1216257781. The reversal of 1216257769 is 9677526121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1026369369 + 189888400 = 32037^2 + 13780^2 .

It is a cyclic number.

It is not a de Polignac number, because 1216257769 - 2⁹ = 1216257257 is a prime.

It is a super-2 number, since 2×1216257769² = 2958565921305714722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1216257719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608128884 + 608128885.

It is an arithmetic number, because the mean of its divisors is an integer number (608128885).

Almost surely, 2^1216257769 is an apocalyptic number.

It is an amenable number.

1216257769 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216257769 is an equidigital number, since it uses as much as digits as its factorization.

1216257769 is an evil number, because the sum of its binary digits is even.

The product of its digits is 317520, while the sum is 46.

The square root of 1216257769 is about 34874.8873689938. The cubic root of 1216257769 is about 1067.4360742506.

The spelling of 1216257769 in words is "one billion, two hundred sixteen million, two hundred fifty-seven thousand, seven hundred sixty-nine".