28729825 has 6 divisors (see below), whose sum is σ = 35625014. Its totient is φ = 22983840.

The previous prime is 28729819. The next prime is 28729853. The reversal of 28729825 is 52892782.

It can be written as a sum of positive squares in 3 ways, for example, as 10265616 + 18464209 = 3204^2 + 4297^2 .

It is not a de Polignac number, because 28729825 - 2³ = 28729817 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 574572 + ... + 574621.

Almost surely, 2^28729825 is an apocalyptic number.

28729825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28729825 is a deficient number, since it is larger than the sum of its proper divisors (6895189).

28729825 is a wasteful number, since it uses less digits than its factorization.

28729825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1149203 (or 1149198 counting only the distinct ones).

The product of its digits is 161280, while the sum is 43.

The square root of 28729825 is about 5360.0209887649. The cubic root of 28729825 is about 306.2746086015.

The spelling of 28729825 in words is "twenty-eight million, seven hundred twenty-nine thousand, eight hundred twenty-five".