1216681615 has 8 divisors (see below), whose sum is σ = 1460340000. Its totient is φ = 973130592.

The previous prime is 1216681597. The next prime is 1216681649. The reversal of 1216681615 is 5161866121.

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

It is a cyclic number.

It is not a de Polignac number, because 1216681615 - 2¹¹ = 1216679567 is a prime.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 657 + ... + 49333.

It is an arithmetic number, because the mean of its divisors is an integer number (182542500).

Almost surely, 2^1216681615 is an apocalyptic number.

1216681615 is a deficient number, since it is larger than the sum of its proper divisors (243658385).

1216681615 is an equidigital number, since it uses as much as digits as its factorization.

1216681615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53681.

The product of its digits is 17280, while the sum is 37.

The square root of 1216681615 is about 34880.9635044676. The cubic root of 1216681615 is about 1067.5600545387.

The spelling of 1216681615 in words is "one billion, two hundred sixteen million, six hundred eighty-one thousand, six hundred fifteen".