28430729 has 4 divisors (see below), whose sum is σ = 28521876. Its totient is φ = 28339584.

The previous prime is 28430693. The next prime is 28430741. The reversal of 28430729 is 92703482.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6901129 + 21529600 = 2627^2 + 4640^2 .

It is a cyclic number.

It is not a de Polignac number, because 28430729 - 2¹² = 28426633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28430029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45104 + ... + 45729.

It is an arithmetic number, because the mean of its divisors is an integer number (7130469).

Almost surely, 2^28430729 is an apocalyptic number.

It is an amenable number.

28430729 is a deficient number, since it is larger than the sum of its proper divisors (91147).

28430729 is an equidigital number, since it uses as much as digits as its factorization.

28430729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91146.

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

The square root of 28430729 is about 5332.0473553786. The cubic root of 28430729 is about 305.2080601327.

It can be divided in two parts, 284 and 30729, that added together give a palindrome (31013).

The spelling of 28430729 in words is "twenty-eight million, four hundred thirty thousand, seven hundred twenty-nine".