28406864 has 40 divisors (see below), whose sum is σ = 58699368. Its totient is φ = 13271040.

The previous prime is 28406839. The next prime is 28406879. The reversal of 28406864 is 46860482.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 7795264 + 20611600 = 2792^2 + 4540^2 .

It is a congruent number.

It is an unprimeable number.

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, 48944 + ... + 49520.

Almost surely, 2^28406864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28406864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29349684).

28406864 is an abundant number, since it is smaller than the sum of its proper divisors (30292504).

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

28406864 is a wasteful number, since it uses less digits than its factorization.

28406864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 783 (or 777 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 38.

The square root of 28406864 is about 5329.8090022064. The cubic root of 28406864 is about 305.1226381312.

The spelling of 28406864 in words is "twenty-eight million, four hundred six thousand, eight hundred sixty-four".