280748639 has 2 divisors, whose sum is σ = 280748640. Its totient is φ = 280748638.

The previous prime is 280748581. The next prime is 280748647. The reversal of 280748639 is 936847082.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 280748639 - 2¹⁶ = 280683103 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 280748593 and 280748602.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (280748669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140374319 + 140374320.

It is an arithmetic number, because the mean of its divisors is an integer number (140374320).

Almost surely, 2^280748639 is an apocalyptic number.

280748639 is a deficient number, since it is larger than the sum of its proper divisors (1).

280748639 is an equidigital number, since it uses as much as digits as its factorization.

280748639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 580608, while the sum is 47.

The square root of 280748639 is about 16755.5554667698. Note that the first 3 decimals coincide. The cubic root of 280748639 is about 654.7958021672.

The spelling of 280748639 in words is "two hundred eighty million, seven hundred forty-eight thousand, six hundred thirty-nine".