1216542247 has 4 divisors (see below), whose sum is σ = 1216612096. Its totient is φ = 1216472400.

The previous prime is 1216542227. The next prime is 1216542319. The reversal of 1216542247 is 7422456121.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1216542247 - 2¹⁵ = 1216509479 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 (1216542227) 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, 14803 + ... + 51499.

It is an arithmetic number, because the mean of its divisors is an integer number (304153024).

Almost surely, 2^1216542247 is an apocalyptic number.

1216542247 is a deficient number, since it is larger than the sum of its proper divisors (69849).

1216542247 is an equidigital number, since it uses as much as digits as its factorization.

1216542247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69848.

The product of its digits is 26880, while the sum is 34.

The square root of 1216542247 is about 34878.9656813387. The cubic root of 1216542247 is about 1067.5192908228.

Adding to 1216542247 its reverse (7422456121), we get a palindrome (8638998368).

The spelling of 1216542247 in words is "one billion, two hundred sixteen million, five hundred forty-two thousand, two hundred forty-seven".