28821416 has 32 divisors (see below), whose sum is σ = 58817640. Its totient is φ = 13160448.

The previous prime is 28821407. The next prime is 28821427. The reversal of 28821416 is 61412882.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 21585316 + 7236100 = 4646^2 + 2690^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8660 + ... + 11516.

Almost surely, 2^28821416 is an apocalyptic number.

28821416 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28821416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29408820).

28821416 is an abundant number, since it is smaller than the sum of its proper divisors (29996224).

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

28821416 is a wasteful number, since it uses less digits than its factorization.

28821416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2973 (or 2969 counting only the distinct ones).

The product of its digits is 6144, while the sum is 32.

The square root of 28821416 is about 5368.5580931941. The cubic root of 28821416 is about 306.5997322936.

The spelling of 28821416 in words is "twenty-eight million, eight hundred twenty-one thousand, four hundred sixteen".