278489640 has 128 divisors (see below), whose sum is σ = 981590400. Its totient is φ = 62315520.

The previous prime is 278489611. The next prime is 278489657. The reversal of 278489640 is 46984872.

It is a self number, because there is not a number n which added to its sum of digits gives 278489640.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9046 + ... + 25274.

It is an arithmetic number, because the mean of its divisors is an integer number (7668675).

Almost surely, 2^278489640 is an apocalyptic number.

278489640 is a gapful number since it is divisible by the number (20) 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 278489640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (490795200).

278489640 is an abundant number, since it is smaller than the sum of its proper divisors (703100760).

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

278489640 is a wasteful number, since it uses less digits than its factorization.

278489640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16267 (or 16263 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 48.

The square root of 278489640 is about 16688.0088686458. The cubic root of 278489640 is about 653.0348340231.

The spelling of 278489640 in words is "two hundred seventy-eight million, four hundred eighty-nine thousand, six hundred forty".