1217312155 has 16 divisors (see below), whose sum is σ = 1496072160. Its totient is φ = 950358528.

The previous prime is 1217312137. The next prime is 1217312167. The reversal of 1217312155 is 5512137121.

It is a cyclic number.

It is not a de Polignac number, because 1217312155 - 2¹⁷ = 1217181083 is a prime.

It is a super-4 number, since 4×1217312155⁴ (a number of 37 digits) contains 4444 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 365779 + ... + 369091.

It is an arithmetic number, because the mean of its divisors is an integer number (93504510).

Almost surely, 2^1217312155 is an apocalyptic number.

1217312155 is a deficient number, since it is larger than the sum of its proper divisors (278760005).

1217312155 is a wasteful number, since it uses less digits than its factorization.

1217312155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5070.

The product of its digits is 2100, while the sum is 28.

The square root of 1217312155 is about 34890.0007881914. Note that the first 3 decimals coincide. The cubic root of 1217312155 is about 1067.7444421545.

Adding to 1217312155 its reverse (5512137121), we get a palindrome (6729449276).

The spelling of 1217312155 in words is "one billion, two hundred seventeen million, three hundred twelve thousand, one hundred fifty-five".