28215716 has 24 divisors (see below), whose sum is σ = 53275320. Its totient is φ = 13025792.

The previous prime is 28215713. The next prime is 28215727. The reversal of 28215716 is 61751282.

It can be written as a sum of positive squares in 4 ways, for example, as 5271616 + 22944100 = 2296^2 + 4790^2 .

It is a super-2 number, since 2×28215716² = 1592253258785312, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28215713) 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, 311 + ... + 7518.

It is an arithmetic number, because the mean of its divisors is an integer number (2219805).

Almost surely, 2^28215716 is an apocalyptic number.

It is an amenable number.

28215716 is a deficient number, since it is larger than the sum of its proper divisors (25059604).

28215716 is a wasteful number, since it uses less digits than its factorization.

28215716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7903 (or 7901 counting only the distinct ones).

The product of its digits is 6720, while the sum is 32.

The square root of 28215716 is about 5311.8467598379. The cubic root of 28215716 is about 304.4367136324.

Adding to 28215716 its reverse (61751282), we get a palindrome (89966998).

The spelling of 28215716 in words is "twenty-eight million, two hundred fifteen thousand, seven hundred sixteen".