280378005 has 24 divisors (see below), whose sum is σ = 451948512. Its totient is φ = 148426752.

The previous prime is 280377961. The next prime is 280378009. The reversal of 280378005 is 500873082.

It is not a de Polignac number, because 280378005 - 2¹⁰ = 280376981 is a prime.

It is a super-2 number, since 2×280378005² = 157223651375560050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (280378009) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 990594 + ... + 990876.

It is an arithmetic number, because the mean of its divisors is an integer number (18831188).

Almost surely, 2^280378005 is an apocalyptic number.

It is an amenable number.

280378005 is a deficient number, since it is larger than the sum of its proper divisors (171570507).

280378005 is an equidigital number, since it uses as much as digits as its factorization.

280378005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 805 (or 548 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 280378005 is about 16744.4917808813. The cubic root of 280378005 is about 654.5075295173.

It can be divided in two parts, 2803 and 78005, that added together give a palindrome (80808).

The spelling of 280378005 in words is "two hundred eighty million, three hundred seventy-eight thousand, five".