1216220263 has 4 divisors (see below), whose sum is σ = 1216468080. Its totient is φ = 1215972448.

The previous prime is 1216220251. The next prime is 1216220281. The reversal of 1216220263 is 3620226121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3620226121 = 4549 ⋅795829.

It is a cyclic number.

It is not a de Polignac number, because 1216220263 - 2²¹ = 1214123111 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 (1216220063) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 116395 + ... + 126412.

It is an arithmetic number, because the mean of its divisors is an integer number (304117020).

Almost surely, 2^1216220263 is an apocalyptic number.

1216220263 is a deficient number, since it is larger than the sum of its proper divisors (247817).

1216220263 is an equidigital number, since it uses as much as digits as its factorization.

1216220263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247816.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 1216220263 is about 34874.3496426815. The cubic root of 1216220263 is about 1067.4251018866.

Adding to 1216220263 its reverse (3620226121), we get a palindrome (4836446384).

The spelling of 1216220263 in words is "one billion, two hundred sixteen million, two hundred twenty thousand, two hundred sixty-three".