280748221 has 8 divisors (see below), whose sum is σ = 302661464. Its totient is φ = 258880320.

The previous prime is 280748219. The next prime is 280748227. The reversal of 280748221 is 122847082.

It can be written as a sum of positive squares in 4 ways, for example, as 25100100 + 255648121 = 5010^2 + 15989^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 280748221 - 2¹ = 280748219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (280748227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2131 + ... + 23791.

It is an arithmetic number, because the mean of its divisors is an integer number (37832683).

Almost surely, 2^280748221 is an apocalyptic number.

It is an amenable number.

280748221 is a deficient number, since it is larger than the sum of its proper divisors (21913243).

280748221 is a wasteful number, since it uses less digits than its factorization.

280748221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22671.

The product of its (nonzero) digits is 14336, while the sum is 34.

The square root of 280748221 is about 16755.5429932903. The cubic root of 280748221 is about 654.7954771971.

The spelling of 280748221 in words is "two hundred eighty million, seven hundred forty-eight thousand, two hundred twenty-one".