280387 has 4 divisors (see below), whose sum is σ = 281736. Its totient is φ = 279040.

The previous prime is 280373. The next prime is 280409. The reversal of 280387 is 783082.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-280387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (280327) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 289 + ... + 802.

It is an arithmetic number, because the mean of its divisors is an integer number (70434).

2²⁸⁰³⁸⁷ is an apocalyptic number.

280387 is a deficient number, since it is larger than the sum of its proper divisors (1349).

280387 is a wasteful number, since it uses less digits than its factorization.

280387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1348.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 280387 is about 529.5158165721. The cubic root of 280387 is about 65.4514528678.

The spelling of 280387 in words is "two hundred eighty thousand, three hundred eighty-seven".