278961648 has 160 divisors (see below), whose sum is σ = 891133440. Its totient is φ = 73405440.

The previous prime is 278961647. The next prime is 278961649. The reversal of 278961648 is 846169872.

It is an interprime number because it is at equal distance from previous prime (278961647) and next prime (278961649).

It is a self number, because there is not a number n which added to its sum of digits gives 278961648.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (278961647) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 235618 + ... + 236798.

It is an arithmetic number, because the mean of its divisors is an integer number (5569584).

Almost surely, 2^278961648 is an apocalyptic number.

278961648 is a gapful number since it is divisible by the number (28) 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 278961648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (445566720).

278961648 is an abundant number, since it is smaller than the sum of its proper divisors (612171792).

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

278961648 is a wasteful number, since it uses less digits than its factorization.

278961648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1255 (or 1249 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 51.

The square root of 278961648 is about 16702.1450119438. The cubic root of 278961648 is about 653.4035654982.

The spelling of 278961648 in words is "two hundred seventy-eight million, nine hundred sixty-one thousand, six hundred forty-eight".