278486640 has 160 divisors (see below), whose sum is σ = 990412800. Its totient is φ = 71850240.

The previous prime is 278486617. The next prime is 278486657. The reversal of 278486640 is 46684872.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

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 pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 64881 + ... + 69039.

It is an arithmetic number, because the mean of its divisors is an integer number (6190080).

Almost surely, 2^278486640 is an apocalyptic number.

278486640 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 278486640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (495206400).

278486640 is an abundant number, since it is smaller than the sum of its proper divisors (711926160).

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

278486640 is a wasteful number, since it uses less digits than its factorization.

278486640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4212 (or 4200 counting only the distinct ones).

The product of its (nonzero) digits is 516096, while the sum is 45.

The square root of 278486640 is about 16687.9189835042. The cubic root of 278486640 is about 653.0324890986.

The spelling of 278486640 in words is "two hundred seventy-eight million, four hundred eighty-six thousand, six hundred forty".