1218831877 has 2 divisors, whose sum is σ = 1218831878. Its totient is φ = 1218831876.

The previous prime is 1218831851. The next prime is 1218831959. The reversal of 1218831877 is 7781388121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1067394241 + 151437636 = 32671^2 + 12306^2 .

It is a cyclic number.

It is not a de Polignac number, because 1218831877 - 2²⁷ = 1084614149 is a prime.

It is a super-2 number, since 2×1218831877² = 2971102288782686258, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1218831277) 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 as a sum of consecutive naturals, namely, 609415938 + 609415939.

It is an arithmetic number, because the mean of its divisors is an integer number (609415939).

Almost surely, 2^1218831877 is an apocalyptic number.

It is an amenable number.

1218831877 is a deficient number, since it is larger than the sum of its proper divisors (1).

1218831877 is an equidigital number, since it uses as much as digits as its factorization.

1218831877 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 150528, while the sum is 46.

The square root of 1218831877 is about 34911.7727564786. The cubic root of 1218831877 is about 1068.1885900581.

The spelling of 1218831877 in words is "one billion, two hundred eighteen million, eight hundred thirty-one thousand, eight hundred seventy-seven".