28403729 has 2 divisors, whose sum is σ = 28403730. Its totient is φ = 28403728.

The previous prime is 28403717. The next prime is 28403741. The reversal of 28403729 is 92730482.

It is a balanced prime because it is at equal distance from previous prime (28403717) and next prime (28403741).

It can be written as a sum of positive squares in only one way, i.e., 14326225 + 14077504 = 3785^2 + 3752^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28403729 is a prime.

It is a super-2 number, since 2×28403729² = 1613543642210882, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (28403029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14201864 + 14201865.

It is an arithmetic number, because the mean of its divisors is an integer number (14201865).

Almost surely, 2^28403729 is an apocalyptic number.

It is an amenable number.

28403729 is a deficient number, since it is larger than the sum of its proper divisors (1).

28403729 is an equidigital number, since it uses as much as digits as its factorization.

28403729 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 35.

The square root of 28403729 is about 5329.5148934964. The cubic root of 28403729 is about 305.1114132072. Note that the first 3 decimals are identical.

The spelling of 28403729 in words is "twenty-eight million, four hundred three thousand, seven hundred twenty-nine".