280400028 has 12 divisors (see below), whose sum is σ = 654266760. Its totient is φ = 93466672.

The previous prime is 280400017. The next prime is 280400041. The reversal of 280400028 is 820004082.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 280399980 and 280400007.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11683323 + ... + 11683346.

It is an arithmetic number, because the mean of its divisors is an integer number (54522230).

Almost surely, 2^280400028 is an apocalyptic number.

It is an amenable number.

280400028 is an abundant number, since it is smaller than the sum of its proper divisors (373866732).

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

280400028 is a wasteful number, since it uses less digits than its factorization.

280400028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23366676 (or 23366674 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 24.

The square root of 280400028 is about 16745.1493872106. The cubic root of 280400028 is about 654.5246657188.

The spelling of 280400028 in words is "two hundred eighty million, four hundred thousand, twenty-eight".