280628 has 6 divisors (see below), whose sum is σ = 491106. Its totient is φ = 140312.

The previous prime is 280627. The next prime is 280639. The reversal of 280628 is 826082.

It can be written as a sum of positive squares in only one way, i.e., 195364 + 85264 = 442^2 + 292^2 .

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 280597 and 280606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (280627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35075 + ... + 35082.

It is an arithmetic number, because the mean of its divisors is an integer number (81851).

2²⁸⁰⁶²⁸ is an apocalyptic number.

It is an amenable number.

280628 is a deficient number, since it is larger than the sum of its proper divisors (210478).

280628 is a wasteful number, since it uses less digits than its factorization.

280628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70161 (or 70159 counting only the distinct ones).

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

The square root of 280628 is about 529.7433340779. The cubic root of 280628 is about 65.4701999126.

The spelling of 280628 in words is "two hundred eighty thousand, six hundred twenty-eight".