280405408 has 48 divisors (see below), whose sum is σ = 584448480. Its totient is φ = 132201216.

The previous prime is 280405373. The next prime is 280405409. The reversal of 280405408 is 804504082.

It is a self number, because there is not a number n which added to its sum of digits gives 280405408.

It is not an unprimeable number, because it can be changed into a prime (280405409) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36391 + ... + 43417.

It is an arithmetic number, because the mean of its divisors is an integer number (12176010).

Almost surely, 2^280405408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 280405408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (292224240).

280405408 is an abundant number, since it is smaller than the sum of its proper divisors (304043072).

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

280405408 is a wasteful number, since it uses less digits than its factorization.

280405408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7109 (or 7101 counting only the distinct ones).

The product of its (nonzero) digits is 10240, while the sum is 31.

The square root of 280405408 is about 16745.3100299756. The cubic root of 280405408 is about 654.5288517861.

The spelling of 280405408 in words is "two hundred eighty million, four hundred five thousand, four hundred eight".