280424821 has 2 divisors, whose sum is σ = 280424822. Its totient is φ = 280424820.

The previous prime is 280424803. The next prime is 280424831. The reversal of 280424821 is 128424082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 278422596 + 2002225 = 16686^2 + 1415^2 .

It is a cyclic number.

It is not a de Polignac number, because 280424821 - 2¹¹ = 280422773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (280424831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140212410 + 140212411.

It is an arithmetic number, because the mean of its divisors is an integer number (140212411).

Almost surely, 2^280424821 is an apocalyptic number.

It is an amenable number.

280424821 is a deficient number, since it is larger than the sum of its proper divisors (1).

280424821 is an equidigital number, since it uses as much as digits as its factorization.

280424821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8192, while the sum is 31.

The square root of 280424821 is about 16745.8896747829. The cubic root of 280424821 is about 654.5439561969.

The spelling of 280424821 in words is "two hundred eighty million, four hundred twenty-four thousand, eight hundred twenty-one".