280408889 has 2 divisors, whose sum is σ = 280408890. Its totient is φ = 280408888.

The previous prime is 280408879. The next prime is 280408913. The reversal of 280408889 is 988804082.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 273075625 + 7333264 = 16525^2 + 2708^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-280408889 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (280408879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140204444 + 140204445.

It is an arithmetic number, because the mean of its divisors is an integer number (140204445).

Almost surely, 2^280408889 is an apocalyptic number.

It is an amenable number.

280408889 is a deficient number, since it is larger than the sum of its proper divisors (1).

280408889 is an equidigital number, since it uses as much as digits as its factorization.

280408889 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 294912, while the sum is 47.

The square root of 280408889 is about 16745.4139692036. The cubic root of 280408889 is about 654.5315602521.

The spelling of 280408889 in words is "two hundred eighty million, four hundred eight thousand, eight hundred eighty-nine".