28270421 has 2 divisors, whose sum is σ = 28270422. Its totient is φ = 28270420.

The previous prime is 28270391. The next prime is 28270433. The reversal of 28270421 is 12407282.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23902321 + 4368100 = 4889^2 + 2090^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28270421 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28270471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14135210 + 14135211.

It is an arithmetic number, because the mean of its divisors is an integer number (14135211).

Almost surely, 2^28270421 is an apocalyptic number.

It is an amenable number.

28270421 is a deficient number, since it is larger than the sum of its proper divisors (1).

28270421 is an equidigital number, since it uses as much as digits as its factorization.

28270421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 28270421 is about 5316.9936054127. The cubic root of 28270421 is about 304.6333352465.

The spelling of 28270421 in words is "twenty-eight million, two hundred seventy thousand, four hundred twenty-one".