1218156155 has 4 divisors (see below), whose sum is σ = 1461787392. Its totient is φ = 974524920.

The previous prime is 1218156133. The next prime is 1218156157. The reversal of 1218156155 is 5516518121.

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

It is not a de Polignac number, because 1218156155 - 2⁸ = 1218155899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1218156157) 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, 121815611 + ... + 121815620.

It is an arithmetic number, because the mean of its divisors is an integer number (365446848).

Almost surely, 2^1218156155 is an apocalyptic number.

1218156155 is a deficient number, since it is larger than the sum of its proper divisors (243631237).

1218156155 is an equidigital number, since it uses as much as digits as its factorization.

1218156155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243631236.

The product of its digits is 12000, while the sum is 35.

The square root of 1218156155 is about 34902.0938483639. The cubic root of 1218156155 is about 1067.9911518459.

The spelling of 1218156155 in words is "one billion, two hundred eighteen million, one hundred fifty-six thousand, one hundred fifty-five".