280681 has 2 divisors, whose sum is σ = 280682. Its totient is φ = 280680.

The previous prime is 280673. The next prime is 280697. The reversal of 280681 is 186082.

280681 is an esthetic number in base 13, because in such base its adjacent digits differ by 1.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 147456 + 133225 = 384^2 + 365^2 .

It is a cyclic number.

It is not a de Polignac number, because 280681 - 2³ = 280673 is a prime.

It is a super-2 number, since 2×280681² = 157563647522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (284681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140340 + 140341.

It is an arithmetic number, because the mean of its divisors is an integer number (140341).

2²⁸⁰⁶⁸¹ is an apocalyptic number.

It is an amenable number.

280681 is a deficient number, since it is larger than the sum of its proper divisors (1).

280681 is an equidigital number, since it uses as much as digits as its factorization.

280681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 280681 is about 529.7933559417. The cubic root of 280681 is about 65.4743212669.

It can be divided in two parts, 280 and 681, that added together give a square (961 = 31²).

The spelling of 280681 in words is "two hundred eighty thousand, six hundred eighty-one".