280649 has 4 divisors (see below), whose sum is σ = 295440. Its totient is φ = 265860.

The previous prime is 280639. The next prime is 280673. The reversal of 280649 is 946082.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 280649 - 2¹² = 276553 is a prime.

It is a super-2 number, since 2×280649² = 157527722402, which contains 22 as substring.

It is a d-powerful number, because it can be written as 2⁷ + 8³ + 6⁷ + 0 + 4³ + 9 .

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 280649.

It is not an unprimeable number, because it can be changed into a prime (280639) 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, 7367 + ... + 7404.

It is an arithmetic number, because the mean of its divisors is an integer number (73860).

2²⁸⁰⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

280649 is a deficient number, since it is larger than the sum of its proper divisors (14791).

280649 is a wasteful number, since it uses less digits than its factorization.

280649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14790.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 280649 is about 529.7631546267. The cubic root of 280649 is about 65.4718329641.

It can be divided in two parts, 280 and 649, that added together give a palindrome (929).

The spelling of 280649 in words is "two hundred eighty thousand, six hundred forty-nine".