1216155125 has 8 divisors (see below), whose sum is σ = 1517761752. Its totient is φ = 972924000.

The previous prime is 1216155113. The next prime is 1216155133. The reversal of 1216155125 is 5215516121.

It can be written as a sum of positive squares in 4 ways, for example, as 158734801 + 1057420324 = 12599^2 + 32518^2 .

It is not a de Polignac number, because 1216155125 - 2²⁰ = 1215106549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 4864496 + ... + 4864745.

It is an arithmetic number, because the mean of its divisors is an integer number (189720219).

Almost surely, 2^1216155125 is an apocalyptic number.

It is an amenable number.

1216155125 is a deficient number, since it is larger than the sum of its proper divisors (301606627).

1216155125 is an frugal number, since it uses more digits than its factorization.

1216155125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9729256 (or 9729246 counting only the distinct ones).

The product of its digits is 3000, while the sum is 29.

The square root of 1216155125 is about 34873.4157346251. The cubic root of 1216155125 is about 1067.4060452569.

The spelling of 1216155125 in words is "one billion, two hundred sixteen million, one hundred fifty-five thousand, one hundred twenty-five".