1217155 has 4 divisors (see below), whose sum is σ = 1460592. Its totient is φ = 973720.

The previous prime is 1217147. The next prime is 1217171. The reversal of 1217155 is 5517121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5517121 = 73 ⋅75577.

It is not a de Polignac number, because 1217155 - 2³ = 1217147 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121711 + ... + 121720.

It is an arithmetic number, because the mean of its divisors is an integer number (365148).

2^1217155 is an apocalyptic number.

1217155 is a deficient number, since it is larger than the sum of its proper divisors (243437).

1217155 is an equidigital number, since it uses as much as digits as its factorization.

1217155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243436.

The product of its digits is 350, while the sum is 22.

The square root of 1217155 is about 1103.2474790363. The cubic root of 1217155 is about 106.7698491574.

It can be divided in two parts, 1 and 217155, that added together give a square (217156 = 466²).

The spelling of 1217155 in words is "one million, two hundred seventeen thousand, one hundred fifty-five".