28351009 has 8 divisors (see below), whose sum is σ = 29601000. Its totient is φ = 27119232.

The previous prime is 28351007. The next prime is 28351027. The reversal of 28351009 is 90015382.

It can be written as a sum of positive squares in 4 ways, for example, as 7006609 + 21344400 = 2647^2 + 4620^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28351009 - 2¹ = 28351007 is a prime.

It is a super-2 number, since 2×28351009² = 1607559422636162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28351007) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1324 + ... + 7645.

It is an arithmetic number, because the mean of its divisors is an integer number (3700125).

Almost surely, 2^28351009 is an apocalyptic number.

28351009 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

28351009 is a deficient number, since it is larger than the sum of its proper divisors (1249991).

28351009 is a wasteful number, since it uses less digits than its factorization.

28351009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9107.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 28351009 is about 5324.5665551292. The cubic root of 28351009 is about 304.9225244404.

It can be divided in two parts, 2835 and 1009, that added together give a square (3844 = 62²).

The spelling of 28351009 in words is "twenty-eight million, three hundred fifty-one thousand, nine".