1216111503 has 8 divisors (see below), whose sum is σ = 1624584448. Its totient is φ = 809189784.

The previous prime is 1216111489. The next prime is 1216111513. The reversal of 1216111503 is 3051116121.

It is a happy number.

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

It is not a de Polignac number, because 1216111503 - 2¹⁰ = 1216110479 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1216111503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216111513) 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, 385975 + ... + 389112.

It is an arithmetic number, because the mean of its divisors is an integer number (203073056).

Almost surely, 2^1216111503 is an apocalyptic number.

1216111503 is a deficient number, since it is larger than the sum of its proper divisors (408472945).

1216111503 is an equidigital number, since it uses as much as digits as its factorization.

1216111503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 775613.

The product of its (nonzero) digits is 180, while the sum is 21.

The square root of 1216111503 is about 34872.7902955872. The cubic root of 1216111503 is about 1067.3932829203.

Adding to 1216111503 its reverse (3051116121), we get a palindrome (4267227624).

The spelling of 1216111503 in words is "one billion, two hundred sixteen million, one hundred eleven thousand, five hundred three".