1218555742540 has 24 divisors (see below), whose sum is σ = 2576141341200. Its totient is φ = 484151005248.

The previous prime is 1218555742513. The next prime is 1218555742541. The reversal of 1218555742540 is 452475558121.

It is not an unprimeable number, because it can be changed into a prime (1218555742541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 204452682 + ... + 204458641.

It is an arithmetic number, because the mean of its divisors is an integer number (107339222550).

Almost surely, 2^{1218555742540} is an apocalyptic number.

1218555742540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1218555742540 is an abundant number, since it is smaller than the sum of its proper divisors (1357585598660).

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

1218555742540 is a wasteful number, since it uses less digits than its factorization.

1218555742540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 408911481 (or 408911479 counting only the distinct ones).

The product of its (nonzero) digits is 2240000, while the sum is 49.

The spelling of 1218555742540 in words is "one trillion, two hundred eighteen billion, five hundred fifty-five million, seven hundred forty-two thousand, five hundred forty".