280021249 has 6 divisors (see below), whose sum is σ = 282947334. Its totient is φ = 277125120.

The previous prime is 280021237. The next prime is 280021279. The reversal of 280021249 is 942120082.

It can be written as a sum of positive squares in 3 ways, for example, as 6350400 + 273670849 = 2520^2 + 16543^2 .

It is not a de Polignac number, because 280021249 - 2¹³ = 280013057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (280021219) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5472 + ... + 24289.

It is an arithmetic number, because the mean of its divisors is an integer number (47157889).

Almost surely, 2^280021249 is an apocalyptic number.

It is an amenable number.

280021249 is a deficient number, since it is larger than the sum of its proper divisors (2926085).

280021249 is an frugal number, since it uses more digits than its factorization.

280021249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29955 (or 29858 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 280021249 is about 16733.8354539538. The cubic root of 280021249 is about 654.2298108782.

The spelling of 280021249 in words is "two hundred eighty million, twenty-one thousand, two hundred forty-nine".