1218279920 has 160 divisors (see below), whose sum is σ = 3361659840. Its totient is φ = 404766720.

The previous prime is 1218279919. The next prime is 1218279941. The reversal of 1218279920 is 299728121.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1246472 + ... + 1247448.

It is an arithmetic number, because the mean of its divisors is an integer number (21010374).

Almost surely, 2^1218279920 is an apocalyptic number.

1218279920 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 1218279920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1680829920).

1218279920 is an abundant number, since it is smaller than the sum of its proper divisors (2143379920).

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

1218279920 is a wasteful number, since it uses less digits than its factorization.

1218279920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1123 (or 1117 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 41.

The square root of 1218279920 is about 34903.8668344927. The cubic root of 1218279920 is about 1068.0273200191.

The spelling of 1218279920 in words is "one billion, two hundred eighteen million, two hundred seventy-nine thousand, nine hundred twenty".