1278915840 has 216 divisors, whose sum is σ = 4658603040. Its totient is φ = 323039232.

The previous prime is 1278915839. The next prime is 1278915889. The reversal of 1278915840 is 485198721.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 215959 + ... + 221801.

Almost surely, 2^1278915840 is an apocalyptic number.

1278915840 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 1278915840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2329301520).

1278915840 is an abundant number, since it is smaller than the sum of its proper divisors (3379687200).

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

1278915840 is a wasteful number, since it uses less digits than its factorization.

1278915840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5889 (or 5872 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 45.

The square root of 1278915840 is about 35761.9328336711. The cubic root of 1278915840 is about 1085.4604118189.

The spelling of 1278915840 in words is "one billion, two hundred seventy-eight million, nine hundred fifteen thousand, eight hundred forty".