280639040 has 112 divisors (see below), whose sum is σ = 741541824. Its totient is φ = 100300800.

The previous prime is 280639039. The next prime is 280639057. The reversal of 280639040 is 40936082.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 280638988 and 280639006.

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 15 ways as a sum of consecutive naturals, for example, 214067 + ... + 215373.

Almost surely, 2^280639040 is an apocalyptic number.

280639040 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 280639040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (370770912).

280639040 is an abundant number, since it is smaller than the sum of its proper divisors (460902784).

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

280639040 is a wasteful number, since it uses less digits than its factorization.

280639040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1396 (or 1386 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 280639040 is about 16752.2846203137. The cubic root of 280639040 is about 654.7105844128.

The spelling of 280639040 in words is "two hundred eighty million, six hundred thirty-nine thousand, forty".