280901221 has 4 divisors (see below), whose sum is σ = 290587500. Its totient is φ = 271214944.

The previous prime is 280901213. The next prime is 280901237. The reversal of 280901221 is 122109082.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 67010596 + 213890625 = 8186^2 + 14625^2 .

It is a cyclic number.

It is not a de Polignac number, because 280901221 - 2³ = 280901213 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 (280901021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4843096 + ... + 4843153.

It is an arithmetic number, because the mean of its divisors is an integer number (72646875).

Almost surely, 2^280901221 is an apocalyptic number.

It is an amenable number.

280901221 is a deficient number, since it is larger than the sum of its proper divisors (9686279).

280901221 is an equidigital number, since it uses as much as digits as its factorization.

280901221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9686278.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 280901221 is about 16760.1080247115. The cubic root of 280901221 is about 654.9144040586.

The spelling of 280901221 in words is "two hundred eighty million, nine hundred one thousand, two hundred twenty-one".