1218210840 has 640 divisors, whose sum is σ = 5394470400. Its totient is φ = 238878720.

The previous prime is 1218210827. The next prime is 1218210841. The reversal of 1218210840 is 480128121.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1218210841) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 4739992 + ... + 4740248.

It is an arithmetic number, because the mean of its divisors is an integer number (8428860).

Almost surely, 2^1218210840 is an apocalyptic number.

1218210840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1218210840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2697235200).

1218210840 is an abundant number, since it is smaller than the sum of its proper divisors (4176259560).

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

1218210840 is a wasteful number, since it uses less digits than its factorization.

1218210840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317 (or 304 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 27.

The square root of 1218210840 is about 34902.8772452931. The cubic root of 1218210840 is about 1068.0071328901.

Adding to 1218210840 its reverse (480128121), we get a palindrome (1698338961).

The spelling of 1218210840 in words is "one billion, two hundred eighteen million, two hundred ten thousand, eight hundred forty".