1216545263 has 2 divisors, whose sum is σ = 1216545264. Its totient is φ = 1216545262.

The previous prime is 1216545259. The next prime is 1216545269. The reversal of 1216545263 is 3625456121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1216545263 - 2² = 1216545259 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1216545269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608272631 + 608272632.

It is an arithmetic number, because the mean of its divisors is an integer number (608272632).

Almost surely, 2^1216545263 is an apocalyptic number.

1216545263 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216545263 is an equidigital number, since it uses as much as digits as its factorization.

1216545263 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43200, while the sum is 35.

The square root of 1216545263 is about 34879.0089165389. The cubic root of 1216545263 is about 1067.5201730050.

The spelling of 1216545263 in words is "one billion, two hundred sixteen million, five hundred forty-five thousand, two hundred sixty-three".