28687729 has 4 divisors (see below), whose sum is σ = 32785984. Its totient is φ = 24589476.

The previous prime is 28687727. The next prime is 28687733. The reversal of 28687729 is 92778682.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28687729 - 2¹ = 28687727 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28687727) 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, 2049117 + ... + 2049130.

It is an arithmetic number, because the mean of its divisors is an integer number (8196496).

Almost surely, 2^28687729 is an apocalyptic number.

It is an amenable number.

28687729 is a deficient number, since it is larger than the sum of its proper divisors (4098255).

28687729 is an equidigital number, since it uses as much as digits as its factorization.

28687729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4098254.

The product of its digits is 677376, while the sum is 49.

The square root of 28687729 is about 5356.0926989738. The cubic root of 28687729 is about 306.1249471942.

The spelling of 28687729 in words is "twenty-eight million, six hundred eighty-seven thousand, seven hundred twenty-nine".