1218239919 has 72 divisors (see below), whose sum is σ = 2057204240. Its totient is φ = 717091056.

The previous prime is 1218239909. The next prime is 1218239963. The reversal of 1218239919 is 9199328121.

It is not a de Polignac number, because 1218239919 - 2⁴ = 1218239903 is a prime.

It is a super-2 number, since 2×1218239919² = 2968217000490253122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1218239909) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 52966942 + ... + 52966964.

Almost surely, 2^1218239919 is an apocalyptic number.

1218239919 is a deficient number, since it is larger than the sum of its proper divisors (838964321).

1218239919 is an frugal number, since it uses more digits than its factorization.

1218239919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92 (or 39 counting only the distinct ones).

The product of its digits is 69984, while the sum is 45.

The square root of 1218239919 is about 34903.2938130486. The cubic root of 1218239919 is about 1068.0156306890.

The spelling of 1218239919 in words is "one billion, two hundred eighteen million, two hundred thirty-nine thousand, nine hundred nineteen".