28631729 has 12 divisors (see below), whose sum is σ = 34456500. Its totient is φ = 23694048.

The previous prime is 28631719. The next prime is 28631731. The reversal of 28631729 is 92713682.

It can be written as a sum of positive squares in 2 ways, for example, as 14077504 + 14554225 = 3752^2 + 3815^2 .

It is a de Polignac number, because none of the positive numbers 2^k-28631729 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28631692 and 28631701.

It is not an unprimeable number, because it can be changed into a prime (28631719) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8654 + ... + 11495.

It is an arithmetic number, because the mean of its divisors is an integer number (2871375).

Almost surely, 2^28631729 is an apocalyptic number.

28631729 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

28631729 is a deficient number, since it is larger than the sum of its proper divisors (5824771).

28631729 is a wasteful number, since it uses less digits than its factorization.

28631729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20192 (or 20185 counting only the distinct ones).

The product of its digits is 36288, while the sum is 38.

The square root of 28631729 is about 5350.8624538480. The cubic root of 28631729 is about 305.9256266201.

The spelling of 28631729 in words is "twenty-eight million, six hundred thirty-one thousand, seven hundred twenty-nine".