28509416 has 32 divisors (see below), whose sum is σ = 57788640. Its totient is φ = 13107648.

The previous prime is 28509413. The next prime is 28509419. The reversal of 28509416 is 61490582.

It is an interprime number because it is at equal distance from previous prime (28509413) and next prime (28509419).

It is a super-2 number, since 2×28509416² = 1625573601322112, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28509413) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48275 + ... + 48861.

It is an arithmetic number, because the mean of its divisors is an integer number (1805895).

Almost surely, 2^28509416 is an apocalyptic number.

28509416 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

28509416 is an abundant number, since it is smaller than the sum of its proper divisors (29279224).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28509416 is a wasteful number, since it uses less digits than its factorization.

28509416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1073 (or 1069 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 28509416 is about 5339.4209423869. The cubic root of 28509416 is about 305.4893729400.

Adding to 28509416 its reverse (61490582), we get a palindrome (89999998).

The spelling of 28509416 in words is "twenty-eight million, five hundred nine thousand, four hundred sixteen".