1216065915 has 12 divisors (see below), whose sum is σ = 2107847664. Its totient is φ = 648568464.

The previous prime is 1216065899. The next prime is 1216065931. The reversal of 1216065915 is 5195606121.

1216065915 is a `hidden beast` number, since 1 + 2 + 1 + 60 + 6 + 591 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (1216065899) and next prime (1216065931).

It is not a de Polignac number, because 1216065915 - 2⁴ = 1216065899 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1216065915.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13511799 + ... + 13511888.

It is an arithmetic number, because the mean of its divisors is an integer number (175653972).

Almost surely, 2^1216065915 is an apocalyptic number.

1216065915 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1216065915 is a deficient number, since it is larger than the sum of its proper divisors (891781749).

1216065915 is a wasteful number, since it uses less digits than its factorization.

1216065915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27023698 (or 27023695 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 36.

The square root of 1216065915 is about 34872.1366566490. The cubic root of 1216065915 is about 1067.3799450717.

The spelling of 1216065915 in words is "one billion, two hundred sixteen million, sixty-five thousand, nine hundred fifteen".