1216001121 has 8 divisors (see below), whose sum is σ = 1706668320. Its totient is φ = 768000672.

The previous prime is 1216001089. The next prime is 1216001123. The reversal of 1216001121 is 1211006121.

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 1216001121 - 2⁵ = 1216001089 is a prime.

It is a super-3 number, since 3×1216001121³ (a number of 28 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1216001121.

It is not an unprimeable number, because it can be changed into a prime (1216001123) 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, 10666620 + ... + 10666733.

It is an arithmetic number, because the mean of its divisors is an integer number (213333540).

Almost surely, 2^1216001121 is an apocalyptic number.

It is an amenable number.

1216001121 is a deficient number, since it is larger than the sum of its proper divisors (490667199).

1216001121 is a wasteful number, since it uses less digits than its factorization.

1216001121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21333375.

The product of its (nonzero) digits is 24, while the sum is 15.

The square root of 1216001121 is about 34871.2076217615. The cubic root of 1216001121 is about 1067.3609874797.

Adding to 1216001121 its reverse (1211006121), we get a palindrome (2427007242).

The spelling of 1216001121 in words is "one billion, two hundred sixteen million, one thousand, one hundred twenty-one".