280840999 has 2 divisors, whose sum is σ = 280841000. Its totient is φ = 280840998.

The previous prime is 280840981. The next prime is 280841009. The reversal of 280840999 is 999048082.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 280840999 - 2⁷ = 280840871 is a prime.

It is a plaindrome in base 11.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (280840909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140420499 + 140420500.

It is an arithmetic number, because the mean of its divisors is an integer number (140420500).

Almost surely, 2^280840999 is an apocalyptic number.

280840999 is a deficient number, since it is larger than the sum of its proper divisors (1).

280840999 is an equidigital number, since it uses as much as digits as its factorization.

280840999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 373248, while the sum is 49.

The square root of 280840999 is about 16758.3113409436. The cubic root of 280840999 is about 654.8675986680.

The spelling of 280840999 in words is "two hundred eighty million, eight hundred forty thousand, nine hundred ninety-nine".