280744421 has 2 divisors, whose sum is σ = 280744422. Its totient is φ = 280744420.

The previous prime is 280744403. The next prime is 280744423. The reversal of 280744421 is 124447082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 262893796 + 17850625 = 16214^2 + 4225^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-280744421 is a prime.

Together with 280744423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (280744423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140372210 + 140372211.

It is an arithmetic number, because the mean of its divisors is an integer number (140372211).

Almost surely, 2^280744421 is an apocalyptic number.

It is an amenable number.

280744421 is a deficient number, since it is larger than the sum of its proper divisors (1).

280744421 is an equidigital number, since it uses as much as digits as its factorization.

280744421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14336, while the sum is 32.

The square root of 280744421 is about 16755.4295975961. The cubic root of 280744421 is about 654.7925229082.

The spelling of 280744421 in words is "two hundred eighty million, seven hundred forty-four thousand, four hundred twenty-one".