1218208831 has 32 divisors (see below), whose sum is σ = 1520318592. Its totient is φ = 952197120.

The previous prime is 1218208811. The next prime is 1218208837. The reversal of 1218208831 is 1388028121.

It is not a de Polignac number, because 1218208831 - 2⁹ = 1218208319 is a prime.

It is a super-2 number, since 2×1218208831² = 2968065511852773122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1218208837) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1483401 + ... + 1484221.

It is an arithmetic number, because the mean of its divisors is an integer number (47509956).

Almost surely, 2^1218208831 is an apocalyptic number.

1218208831 is a deficient number, since it is larger than the sum of its proper divisors (302109761).

1218208831 is a wasteful number, since it uses less digits than its factorization.

1218208831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1219.

The product of its (nonzero) digits is 6144, while the sum is 34.

The square root of 1218208831 is about 34902.8484654190. The cubic root of 1218208831 is about 1068.0065457921.

The spelling of 1218208831 in words is "one billion, two hundred eighteen million, two hundred eight thousand, eight hundred thirty-one".