1216775125 has 16 divisors (see below), whose sum is σ = 1519522992. Its totient is φ = 972787200.

The previous prime is 1216775117. The next prime is 1216775129. The reversal of 1216775125 is 5215776121.

It can be written as a sum of positive squares in 8 ways, for example, as 895326084 + 321449041 = 29922^2 + 17929^2 .

It is not a de Polignac number, because 1216775125 - 2³ = 1216775117 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216775129) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 327277 + ... + 330973.

It is an arithmetic number, because the mean of its divisors is an integer number (94970187).

Almost surely, 2^1216775125 is an apocalyptic number.

It is an amenable number.

1216775125 is a deficient number, since it is larger than the sum of its proper divisors (302747867).

1216775125 is an equidigital number, since it uses as much as digits as its factorization.

1216775125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6345 (or 6335 counting only the distinct ones).

The product of its digits is 29400, while the sum is 37.

The square root of 1216775125 is about 34882.3038946684. The cubic root of 1216775125 is about 1067.5874035132.

The spelling of 1216775125 in words is "one billion, two hundred sixteen million, seven hundred seventy-five thousand, one hundred twenty-five".