1216543413 has 4 divisors (see below), whose sum is σ = 1622057888. Its totient is φ = 811028940.

The previous prime is 1216543411. The next prime is 1216543451. The reversal of 1216543413 is 3143456121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1216543413 - 2¹ = 1216543411 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216543411) 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, 202757233 + ... + 202757238.

It is an arithmetic number, because the mean of its divisors is an integer number (405514472).

Almost surely, 2^1216543413 is an apocalyptic number.

It is an amenable number.

1216543413 is a deficient number, since it is larger than the sum of its proper divisors (405514475).

1216543413 is an equidigital number, since it uses as much as digits as its factorization.

1216543413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405514474.

The product of its digits is 8640, while the sum is 30.

The square root of 1216543413 is about 34878.9823962799. The cubic root of 1216543413 is about 1067.5196318788.

Adding to 1216543413 its reverse (3143456121), we get a palindrome (4359999534).

The spelling of 1216543413 in words is "one billion, two hundred sixteen million, five hundred forty-three thousand, four hundred thirteen".