28121814 has 48 divisors (see below), whose sum is σ = 69957888. Its totient is φ = 7997616.

The previous prime is 28121803. The next prime is 28121827. The reversal of 28121814 is 41812182.

28121814 = 2650² + 2651² + ... + 2653².

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 38319 + ... + 39045.

It is an arithmetic number, because the mean of its divisors is an integer number (1457456).

Almost surely, 2^28121814 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28121814, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34978944).

28121814 is an abundant number, since it is smaller than the sum of its proper divisors (41836074).

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

28121814 is a wasteful number, since it uses less digits than its factorization.

28121814 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1049 (or 1046 counting only the distinct ones).

The product of its digits is 1024, while the sum is 27.

The square root of 28121814 is about 5303.0004714312. Note that the first 3 decimals coincide. The cubic root of 28121814 is about 304.0986161477.

Adding to 28121814 its reverse (41812182), we get a palindrome (69933996).

The spelling of 28121814 in words is "twenty-eight million, one hundred twenty-one thousand, eight hundred fourteen".