280400813 has 8 divisors (see below), whose sum is σ = 349590720. Its totient is φ = 218494080.

The previous prime is 280400759. The next prime is 280400831. The reversal of 280400813 is 318004082.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 280400813 - 2⁸ = 280400557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (280400213) 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, 1820708 + ... + 1820861.

It is an arithmetic number, because the mean of its divisors is an integer number (43698840).

Almost surely, 2^280400813 is an apocalyptic number.

It is an amenable number.

280400813 is a deficient number, since it is larger than the sum of its proper divisors (69189907).

280400813 is a wasteful number, since it uses less digits than its factorization.

280400813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3641587.

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 280400813 is about 16745.1728268179. The cubic root of 280400813 is about 654.5252765145.

Adding to 280400813 its reverse (318004082), we get a palindrome (598404895).

The spelling of 280400813 in words is "two hundred eighty million, four hundred thousand, eight hundred thirteen".