1218687664 has 20 divisors (see below), whose sum is σ = 2485482040. Its totient is φ = 577272960.

The previous prime is 1218687599. The next prime is 1218687667. The reversal of 1218687664 is 4667868121.

It is not an unprimeable number, because it can be changed into a prime (1218687667) 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 in 3 ways as a sum of consecutive naturals, for example, 2004117 + ... + 2004724.

It is an arithmetic number, because the mean of its divisors is an integer number (124274102).

Almost surely, 2^1218687664 is an apocalyptic number.

It is an amenable number.

1218687664 is an abundant number, since it is smaller than the sum of its proper divisors (1266794376).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1218687664 is a wasteful number, since it uses less digits than its factorization.

1218687664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4008868 (or 4008862 counting only the distinct ones).

The product of its digits is 774144, while the sum is 49.

The square root of 1218687664 is about 34909.7073032702. The cubic root of 1218687664 is about 1068.1464588011.

The spelling of 1218687664 in words is "one billion, two hundred eighteen million, six hundred eighty-seven thousand, six hundred sixty-four".