1216445563 has 8 divisors (see below), whose sum is σ = 1220029056. Its totient is φ = 1212868800.

The previous prime is 1216445561. The next prime is 1216445567. The reversal of 1216445563 is 3655446121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1216445563 - 2¹ = 1216445561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1216445561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 753345 + ... + 754957.

It is an arithmetic number, because the mean of its divisors is an integer number (152503632).

Almost surely, 2^1216445563 is an apocalyptic number.

1216445563 is a deficient number, since it is larger than the sum of its proper divisors (3583493).

1216445563 is an equidigital number, since it uses as much as digits as its factorization.

1216445563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3365.

The product of its digits is 86400, while the sum is 37.

The square root of 1216445563 is about 34877.5796608652. The cubic root of 1216445563 is about 1067.4910099117.

The spelling of 1216445563 in words is "one billion, two hundred sixteen million, four hundred forty-five thousand, five hundred sixty-three".