8278640 has 20 divisors (see below), whose sum is σ = 19248024. Its totient is φ = 3311424.

The previous prime is 8278637. The next prime is 8278649. The reversal of 8278640 is 468728.

It is a tau number, because it is divible by the number of its divisors (20).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 8278640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8278649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51662 + ... + 51821.

Almost surely, 2^8278640 is an apocalyptic number.

8278640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

8278640 is an abundant number, since it is smaller than the sum of its proper divisors (10969384).

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

8278640 is a wasteful number, since it uses less digits than its factorization.

8278640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103496 (or 103490 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 35.

The square root of 8278640 is about 2877.2625879471. The cubic root of 8278640 is about 202.2955514140.

The spelling of 8278640 in words is "eight million, two hundred seventy-eight thousand, six hundred forty".