1218911280 has 40 divisors (see below), whose sum is σ = 3778625712. Its totient is φ = 325042944.

The previous prime is 1218911261. The next prime is 1218911293. The reversal of 1218911280 is 821198121.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×1218911280² = 2971489417022476800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2539159 + ... + 2539638.

Almost surely, 2^1218911280 is an apocalyptic number.

1218911280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1218911280 is an abundant number, since it is smaller than the sum of its proper divisors (2559714432).

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

1218911280 is a wasteful number, since it uses less digits than its factorization.

1218911280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5078813 (or 5078807 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 33.

The square root of 1218911280 is about 34912.9099331465. The cubic root of 1218911280 is about 1068.2117859115.

The spelling of 1218911280 in words is "one billion, two hundred eighteen million, nine hundred eleven thousand, two hundred eighty".