1216528871 has 4 divisors (see below), whose sum is σ = 1242412512. Its totient is φ = 1190645232.

The previous prime is 1216528861. The next prime is 1216528879. The reversal of 1216528871 is 1788256121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1788256121 = 20261 ⋅88261.

It is a cyclic number.

It is not a de Polignac number, because 1216528871 - 2²² = 1212334567 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 (1216528879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12941750 + ... + 12941843.

It is an arithmetic number, because the mean of its divisors is an integer number (310603128).

Almost surely, 2^1216528871 is an apocalyptic number.

1216528871 is a deficient number, since it is larger than the sum of its proper divisors (25883641).

1216528871 is an equidigital number, since it uses as much as digits as its factorization.

1216528871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25883640.

The product of its digits is 53760, while the sum is 41.

The square root of 1216528871 is about 34878.7739320063. The cubic root of 1216528871 is about 1067.5153783158.

The spelling of 1216528871 in words is "one billion, two hundred sixteen million, five hundred twenty-eight thousand, eight hundred seventy-one".