1216122361 has 4 divisors (see below), whose sum is σ = 1245783924. Its totient is φ = 1186460800.

The previous prime is 1216122329. The next prime is 1216122367. The reversal of 1216122361 is 1632216121.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 312759225 + 903363136 = 17685^2 + 30056^2 .

It is a cyclic number.

It is not a de Polignac number, because 1216122361 - 2⁵ = 1216122329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1216122367) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14830720 + ... + 14830801.

It is an arithmetic number, because the mean of its divisors is an integer number (311445981).

Almost surely, 2^1216122361 is an apocalyptic number.

It is an amenable number.

1216122361 is a deficient number, since it is larger than the sum of its proper divisors (29661563).

1216122361 is an equidigital number, since it uses as much as digits as its factorization.

1216122361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29661562.

The product of its digits is 864, while the sum is 25.

The square root of 1216122361 is about 34872.9459753546. The cubic root of 1216122361 is about 1067.3964596360.

Adding to 1216122361 its reverse (1632216121), we get a palindrome (2848338482).

The spelling of 1216122361 in words is "one billion, two hundred sixteen million, one hundred twenty-two thousand, three hundred sixty-one".