1216983559521 has 8 divisors (see below), whose sum is σ = 1627546997344. Its totient is φ = 808871247360.

The previous prime is 1216983559489. The next prime is 1216983559559. The reversal of 1216983559521 is 1259553896121.

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

It is not a de Polignac number, because 1216983559521 - 2⁵ = 1216983559489 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1216983559021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 612780256 + ... + 612782241.

It is an arithmetic number, because the mean of its divisors is an integer number (203443374668).

Almost surely, 2^{1216983559521} is an apocalyptic number.

It is an amenable number.

1216983559521 is a deficient number, since it is larger than the sum of its proper divisors (410563437823).

1216983559521 is a wasteful number, since it uses less digits than its factorization.

1216983559521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1225562831.

The product of its digits is 5832000, while the sum is 57.

The spelling of 1216983559521 in words is "one trillion, two hundred sixteen billion, nine hundred eighty-three million, five hundred fifty-nine thousand, five hundred twenty-one".