28215516 has 48 divisors (see below), whose sum is σ = 75591936. Its totient is φ = 8024064.

The previous prime is 28215479. The next prime is 28215527. The reversal of 28215516 is 61551282.

It is a super-2 number, since 2×28215516² = 1592230686292512, which contains 22 as substring.

It is a congruent 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 15 ways as a sum of consecutive naturals, for example, 20935 + ... + 22241.

It is an arithmetic number, because the mean of its divisors is an integer number (1574832).

Almost surely, 2^28215516 is an apocalyptic number.

It is an amenable number.

28215516 is an abundant number, since it is smaller than the sum of its proper divisors (47376420).

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

28215516 is a wasteful number, since it uses less digits than its factorization.

28215516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1578 (or 1576 counting only the distinct ones).

The product of its digits is 4800, while the sum is 30.

The square root of 28215516 is about 5311.8279339602. The cubic root of 28215516 is about 304.4359943231.

Adding to 28215516 its reverse (61551282), we get a palindrome (89766798).

The spelling of 28215516 in words is "twenty-eight million, two hundred fifteen thousand, five hundred sixteen".