281928421 has 2 divisors, whose sum is σ = 281928422. Its totient is φ = 281928420.

The previous prime is 281928379. The next prime is 281928481. The reversal of 281928421 is 124829182.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 168740100 + 113188321 = 12990^2 + 10639^2 .

It is a cyclic number.

It is not a de Polignac number, because 281928421 - 2⁷ = 281928293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (281928481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140964210 + 140964211.

It is an arithmetic number, because the mean of its divisors is an integer number (140964211).

Almost surely, 2^281928421 is an apocalyptic number.

It is an amenable number.

281928421 is a deficient number, since it is larger than the sum of its proper divisors (1).

281928421 is an equidigital number, since it uses as much as digits as its factorization.

281928421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18432, while the sum is 37.

The square root of 281928421 is about 16790.7242547783. The cubic root of 281928421 is about 655.7117302792.

The spelling of 281928421 in words is "two hundred eighty-one million, nine hundred twenty-eight thousand, four hundred twenty-one".