1216824885921 has 8 divisors (see below), whose sum is σ = 1622577352864. Its totient is φ = 811144504800.

The previous prime is 1216824885917. The next prime is 1216824885943. The reversal of 1216824885921 is 1295884286121.

It is a happy number.

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

It is not a de Polignac number, because 1216824885921 - 2² = 1216824885917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1216824885901) 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, 17982055 + ... + 18049596.

It is an arithmetic number, because the mean of its divisors is an integer number (202822169108).

Almost surely, 2^{1216824885921} is an apocalyptic number.

It is an amenable number.

1216824885921 is a deficient number, since it is larger than the sum of its proper divisors (405752466943).

1216824885921 is a wasteful number, since it uses less digits than its factorization.

1216824885921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36042911.

The product of its digits is 4423680, while the sum is 57.

The spelling of 1216824885921 in words is "one trillion, two hundred sixteen billion, eight hundred twenty-four million, eight hundred eighty-five thousand, nine hundred twenty-one".