28703821 has 2 divisors, whose sum is σ = 28703822. Its totient is φ = 28703820.

The previous prime is 28703797. The next prime is 28703827. The reversal of 28703821 is 12830782.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23912100 + 4791721 = 4890^2 + 2189^2 .

It is a cyclic number.

It is not a de Polignac number, because 28703821 - 2⁵ = 28703789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28703827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14351910 + 14351911.

It is an arithmetic number, because the mean of its divisors is an integer number (14351911).

Almost surely, 2^28703821 is an apocalyptic number.

It is an amenable number.

28703821 is a deficient number, since it is larger than the sum of its proper divisors (1).

28703821 is an equidigital number, since it uses as much as digits as its factorization.

28703821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 28703821 is about 5357.5947028494. The cubic root of 28703821 is about 306.1821754008.

The spelling of 28703821 in words is "twenty-eight million, seven hundred three thousand, eight hundred twenty-one".